The OBX Helical Diff Thread!!! Installed in S14!!!

[240shorty]

Finally got my OBX differential a couple of days ago. It's been about a month and a half, thanks to the wonderful folks at UPS. What can brown do for you?? Answer: Lose my packages.

INSTALL: I took 36 pics and was thinking of doing a writeup, but a differential install is a differential install. They are pretty much all the same, so I'll just point out the relevant stuff.

First it was installed into an open differential. There was some question as to which type it would work for. It appears to be designed for the open. The shafts fit in where they should be, flush with the housing, and the depth appears correct also.

I installed the unit myself. I checked the backlash of both the oem unit and the OBX. The OEM @ 140K miles had backlash measurements of .0045, .0055, and .0070. The latter being slightly out of spec. It worked well.

I removed the bearings with a puller and reused them. I used the original ring gear as well. Everything lines up and is cake to install on the OBX. Ring gear applied with red loctite.

BACKLASH: This is important. I DO NOT recommend installing one of these without checking backlash. Some people do it with the s15 diffs, but that is an OEM Nissan part. I tried the OBX with stock shims and the result was ZERO backlash. Spec is .0039 to .0059. The gears interlocked completely with no play whatsoever. I had stock shims of roughly .083 and .103 inches. I thought of swapping sides of the shims, but they would have moved the diff housing the wrong way. I did not have a shim pack, so I cut my own shims. I don't recommend this, but it works. I cut a ~.063 shim from sheet and 6 .005 shims from aluminum cans. Hoffbauer lager, to be exact. I used these shims in combination to eventually get the backlash within spec. I took many measurements ranging from .0035 all the way up to .008. Again, that latter is slightly out of spec, but it is close enough for me, and pretty much the same as the OEM unit.

http://xs67.xs.to/pics/06064/dialindicator.jpg (http://xs.to)

I checked the tooth pattern with prussian blue. It was pretty heel heavy, but I did not intend to adjust the pinion, so it will have to do. This cannot always be adjusted properly anyway, as it depends on the pinion bore to housing alignment.

I should also note regarding bearing preload: I did not have a spring gauge to test preload. The OBX with stock shims, fell into place pretty easily. It required more shims than stock to create some preload. I simply gauged the tension on the OEM diff and tried to duplicate it as nearly as possible. I ended up using all 6 pop can shims as well as the homemade sheet shim, plus the OEM .103 and spacer. I discarded the .083 from the non-toothed side of the diff. I probably ultimately added somewhere between .010 and .020 shims total.

OBX with bearings and ring gear:

http://xs67.xs.to/pics/06064/obxhsld.jpg (http://xs.to)

Including removal and replacing the housing there are several hours of work involved to do the job right, depending of course on working conditions and tools. I did it over the course of a couple nights, off and on, while taking pics and making notes.



REVIEW:

This is a preliminary, first impression type of review. I'll update my impressions over the next couple of days and add any relevant information regarding its performance. And of course, if it breaks.

After the install I took it out for a 20 minute test drive. Normal driving operation is, well, normal. Everything looks good so far. So I took it onto a dirt road first. I stopped in a few different spots, leaving one tire on dry gravel/dirt and the other tire in the ice and hard packed snow. I gave it a little brake and a little gas and let the clutch out to spin the wheels in place. I did this for a couple of seconds at a time to verify that the wheel with the most traction was spinning. The results are as expected. Both tires spun, and the tire with the most traction (dirt) spun continuously. Note: This is hardly scientific, as the application of the brake gives torque to both wheels, really negating the effect that might be experienced without braking. But it does prove that the differential is functioning and transfering torque.

Here is a pic showing the marks left by the tires on dirt and snow:

http://xs67.xs.to/pics/06064/traction.jpg (http://xs.to)

Next I took it to a paved road and parked it once again, half on pavement, half off the road in a snow covered gravel field entrance. I repeated the same methods used on the dirt road and once again the tire on the pavement broke loose. I did this only briefly as my winter tires smoke like the dickens and they are almost new.

I also opened up the throttle a bit on snow covered gravel to compare its response with the open differential. Both wheels spin and the rear end steps out more dramatically and quickly than with the open diff (of course).

This is about the extent of the testing so far. I didn't want to flog the car so fresh off the swap, and I will post more when I do.

In summary. So far, so good. I will update as appropriate.

-Steve

[kabukie]

Finally some posts a review!

Keep us updated!

[SR240DET]

haha i started laughing everytime i read the word "shim'' it started to lose its meaning...

nice write up.. finally somebody did one....

[i8yourfwd]

FINALLY! I'll be keeping my eyes on this thread. :) let us know when you take it for some "spirited driving"

[EvilRB]

great thread man!!
Keep us updated!

[WILDACEX187]

so does the obx unit have a more aggressive torque split than a s15?

[240shorty]

^If you are asking me, I can't answer that. I've not experienced the s15 yet. There is zero documentation that came with the unit. It comes in a white box with a cheap graphic saying 'OBX L.S.D.' and it's just a chunk of metal in a plastic bag. I never even got a reply from them when I emailed about which type diff it fit, so I'm not sure how to find out either.

[krustindumm]

Just an FYI, it only cost me ~$150 to have a differential setup last time (carried in). $50 was for new shims. Worth it, IMO, to have a diff setup properly.

[OptionZero]

I'm not really sure how a comparison to an open diff will be of any use.

What you should compare it to is a Welded Diff and a VLSD, which are the alternatives at a similar price point.

The compare it to the S15 HLSD, because that (and a Quaife...) are the alternative for those wanting a torque biasing diff.

Just saying that this works better than an open diff doesn't accomplish much.

[BigVinnie]

^^^Well atleast it is a better alternative than an open diff. Sucks though because modifying for a LSD diff case might be a bit more difficult, which means any of us that use LSD already really can't source this as an affordable alternative, (without B.S modifying). Which I thought that this is what it was for us LSD guy's.
Thanks for the info Steve, I guess I will look for other types of Torsens or Helicals that would be a direct bolt in for my case............

[ryangreg]

^^No differential is a drop in affair. Many people choose to go that route, but many people are hacks. Backlash must be measured, and dye should be used to see how the ring and pinion mate. If measurements arent taken, your gonna have a diff that is way louder than it was intended to be.

[240shorty]

Yes, I agree, the open differential comparison is pretty much useless. I was just pointing out that the diff was obviously doing it's job. I only have had access to an open and a welded. The welded diff I really don't like. It might be alright for drifting or strip, but daily driven I don't find the sacrifices in drivability acceptable. For me, after driving the welded, it was either stay open or go hlsd or possibly 1.5 way. I don't consider vlsd to be a good performance differential.

I like the fact that the hlsd is not apparent until you need it. No sacrificing drivability. I was a little torn between going S15 hlsd though. To me it is actually more risky to buy a new OBX than a used OEM part. But most of those actually go for more than this one, so... I went ahead and got it.

krustindumm, I have no doubt a shop install is worth it, but I like to learn the stuff myself when it is feasible. I familiarized myself with the steps involved and have enough tools and intelligence to do a fairly competent install. Or maybe I'm just a cheap a$$?

I didn't get to drive it today. My intercooler and piping came, so I did a little cutting and welding. Hopefully tomorrow I can finish up and get a good drive in.

[slideways2004]

can't wait for more of a review.

[gearhead290]

^^No differential is a drop in affair. Many people choose to go that route, but many people are hacks. Backlash must be measured, and dye should be used to see how the ring and pinion mate. If measurements arent taken, your gonna have a diff that is way louder than it was intended to be.

I checked backlash, the R&P pattern, and preload on both my ATS and my buddy's Kaaz...all three were right where they were supposed to be. Many shops don't even check the higher end differentials, just drop them in and go.

[krustindumm]

kristendumm, I have no doubt a shop install is worth it, but I like to learn the stuff myself when it is feasible. I familiarized myself with the steps involved and have enough tools and intelligence to do a fairly competent install. Or maybe I'm just a cheap a$$?

I was just making the post so other people would know that a shop install is a cheap option. Setting up a diff is VERY easy, if you have the right tools and shims on hand. I'm actually a Nissan Technician, but I took mine to a specialty shop because we don't stock shims, and I wanted it done right away. My car is my daily driver, so I can't have 2 days downtime while we order new shims.

[240shorty]

Alright, I was gonna update yesterday, but I kept having problems with my intercooler piping poppin' off. I did manage a couple of short runs, mostly N/A. I did a couple of burnouts/hole shots and the thing held up, but that is no feat for <150 horsepower (restricted intake). I can't comment much on traction though. Wet roads plus winter tires doesn't make for good traction.

I did notice one small thing that I don't particularly like, but I presume it to be normal. When initially releasing the clutch and starting off and on subsequent shifts it is possible to hear or feel a slight delay in the power application. It is very subtle, but I don't recall noticing it on the open. I have my interior out for now, so it is pretty easy to hear and feel everything in the car. I suspect it is the nature of the helical diff, when it's worm gears press outward and direct power to the wheels. I figure it is the mechanical action of the differential causing a momentary delay in power delivery. Perhaps someone with an S15 or Quaife could confirm whether or not this is the case.

Anyway, I did some more work today and welded a couple lips on the trouble areas of the intercooler piping. This time they held up and I got to take a few full throttle runs in it. This is the first time I've gotten to run for a signigicant time with sustained boost. Boost pressure runs between 8 and 10 psi and my timing is retarded to 15* and conservative AFR's around 10.5 to 11. I estimate it is producing somewhere in the ballpark of stock SR power, give or take. I'm still a little hesitant to go full throttle right off the line, I want to make sure everything is kosher and build a bit of confidence in it. But traction is alright and the diff has held up so far.

What I really need is some road coarse type testing or at least some tight cornering. This is of course, why you'd buy an hlsd in the first place. It's still winter here unfortunately, so no tracks will be open for awhile. I will do what I can on the public roads when we get some dry pavement.

Summary, I haven't broke it yet, but give me time. :')

[beavis360]

any update on this?

[tchenku]

i'm trying to keep updated, also. nothing as of yet. nothing on nico, either. either 240shorty is snowed in up where he lives or he's out having the time of his life with the obx lsd and has forgotten to keep us up to date.:p

[240shorty]

i'm trying to keep updated, also. nothing as of yet. nothing on nico, either. either 240shorty is snowed in up where he lives or he's out having the time of his life with the obx lsd and has forgotten to keep us up to date.:p

Well, they say no news is good news right? The differential is still doing fine.

I've been installing the new clutch over the past few days. I had a throwout bearing/fork issue the first time around, so I pulled it back down and fixed it. It's all good, now, but I'm still in the break in period so I've been taking it easy on the clutch.

I have not had much chance to flog the differential, but it is holding up well so far to my mildly boosted engine and some spirited driving. I just hadn't updated because I don't have any real relevant info to report on. I would like to get some launch times and hard cornering in, but that is still nearly a month off up here. Weather sucks.

Hope this will suffice for now. If not, well... tough luck. :p

Hasn't ANYONE else tried this diff yet?? I'd like to see someone elses thoughts on it. Specifically someone who has driven with an S15, Quaife, or clutch diff in a 240. I have yet to drive any of them. Only open, welded, and OBX. So in my very limited experience, OBX is EASILY the most superior. I'd like to know myself how it compares directly to the 'heavy hitters'.

-Steve

[infinitexsound]

im procrastinating on trying it out seriously, my viscous is goin out...and i would either replace it with a 2way clutch type pref.. a nismo one.. or that obx one to see how well it holds up...

[Skyline0586]

i laughed when i saw OBX..

[AzNCmB]

for the price, i would like to try it because i think my vlsd is going out to0 :(

but....i will do more research on diff installs just to be sure if i can attempt this myself...

please keep us updated..thanks

[nrg]

isn't this just a HLSD? There are tons of reviews on these obx lsd on honda-tech.com
I think there's a 450whp drag car using one.

best way to test this diff is to drift or road race on it.

[KA24DESOneThree]

Do you read AT ALL?

1. It says helical in the thread title.

2. He lives in Michigan. Track time in March in Michigan is hard to come by.

[timtiminy]

okay well i am interested in this soley for grip driving because of the torsen diff is more adequate for handling than drifing. I am looking for some info from 240shorty about the way this thing handles, i am sure its a huge improvement over an open diff. So its spring now...is there still snow or can you go on an dry road and tell me how this thing performs??

[240shorty]

Well, the weather IS better here now and I have been doing some driving. Only on the street though. I like the way it launches; I like the way it feels in corners; I like the fact that it hasn't broken.

I have very limited experience with 240 diffs, but off the line the difference in traction is noticable. I was doing some launching the other day on the street and was fairly impressed with traction out of the hole. Keep in mind I've been driving on 7.5" wide wheels with crap Korean rubber. Any attempt at a hard start with the open diff resulted in a spectacular one tire fire. Even with the crap tires and the helical, I have found it hard to break traction without trying to do so. Raising the revs to around 3k and nearly dropping the clutch did result in some squeeling, but not a full on burnout. The tires did chirp repeatedly, but they got plenty of traction to propel the car forward. I am not skilled in the art of drag launches, but feel that with practice one could do very well with this diff.

In corners, once the car loses traction, it feels very similar to any locking differential. The ass end slides out easily as both tires spin. The big difference though, is that up until you cross that threshold, traction is solid and handling is smooth. I want to make clear this difference. Driving a helical through corners is smooth and well planted, though much will still depend on your tires. Driving my brother's welded through corners is a jerky, un-inspiring proposition. In fairness, a welded is better for drifting (which I don't do) and attracting law enforcement officers (which I don't like to do) and 16 year old rice loving boys (which I hope to hell I don't do).

I have not intentionally neglected this thread, but having not taken this thing to the limit, I cannot give a true and full review of it. It's still 'so far, so good', and time will tell.

The true test will be in a few weeks. My Holset arrives Thursday and my tax refund will be funding my new wheels and tires within ~3 weeks. I also went back to work today finally. So in under a month, barring an act of God, I should be sporting 300+ hp, 10.5 inch wide tires and hopefully a little suspension too. Then I will know without a doubt if the OBX Helical LSD is up to the task.

And I know I'm not the only one who's bought one of these, so where are the rest of the reviews???

To those who are hesitant: It is not that much money to have the diff installed by a shop (from what I've heard). You can get a cheap, but adequate digital dial indicator and base from Harbor Freight. You can pick up Prussian Blue from Car Quest. And you can get free install instructions from F.S. Manual and your good friend Mr. Google.

In the interest of being completely candid and offering full disclosure: I alluded to something I noticed in the drivetrain previously. I will try to describe it more clearly. When the drivetrain goes from an 'unloaded' to a 'loaded' state, there is what I'd describe as a small 'shock loading' that occurs. This is noticable in certain situations and is affected by the type of driving and especially the clutch release. I am not 100% certain of the origin, but I have attributed it to the diff as I noticed it shortly after the install. There is a possibility that it is tranny related or possibly compounded by my VERY tired engine mounts. I also have a 6 puck clutch which no doubt makes it more noticable. Bottom line: It might not be noticable with a street disk and it is possibly not even diff related (though I believe it is).

I tell you this so those who may be looking at this diff can make an informed decision. I do consider it a 'minor' annoyance and would still take this diff over any other option, with the possible exception of an S15 or Quaife HLSD. Those IMO are the two relevant comparisons here. The Quaife is not comparable in price, but the S15 is fairly close. It is a question of new OBX vs. used OEM.

OBX pwns Open, period. My personal prejudice towards viscous coupling dictates that OBX > VLSD. For my usage, OBX > welded or any clutch diff. I would guess, but cannot say that Quaife > OBX. They may perform comparably. I am not qualified to make this comparison.

For anyone considering swapping to a VLSD, who isn't into drifting, I'd say you are doing yourself a big disservice if you don't consider this diff. You are going to spend enough time and money for that swap, and subsequently enough time wondering when your viscous is going to turn into an open, that you'd be better of going with this diff.

Whatever. I'm not a salesman or an OBX fanboy so... [/commercial]

Your car. You decide.

[i8yourfwd]

Yay finally an update! thanks for not forgetting about us taht want to hear about it :]

Describe the "shock loading"?

[mikesim]

since i've never looked inside my VLSD, can this OBX install into it without modification? or is it only meant for open diffs?

[240shorty]

See, now that phrase sounds bad. I don't know if it is a good choice. All I am trying to say is that there is a small ammount of 'slop' in my drivetrain somewhere. Let's say I'm cruising around town gently shifting through the gears. When I let of the gas to upshift there is no load on the drivetrain. I upshift and release the clutch. Upon release, there is load put back on the drivetrain. Somewhere in the drivetrain it feels like there is a certain ammount of give between mechanical components. So it will give a little 'clunk' as (or slightly after) the clutch engages the flywheel. It comes after the clutch release, with a momentary delay.

It is not the clutch that makes the 'clunk'. This much I can tell. You can also eliminate it by consciously releasing the clutch more gently. For this reason, I suggest it might be un-noticable with a normal street disk. The source of the give in the drivetrain could very well be my tranny, the rear, or maybe a faulty joint in the rear axles. I cannot say for certain. It could even be bushing related.

I could not give a complete review without including it though, as it may very well come from the rear. That is when I noticed it, so that's where I'd tend to attribute it.

I've gotta get to work, but hopefully this explanation helps to describe it better.

-Steve

[240shorty]

since i've never looked inside my VLSD, can this OBX install into it without modification? or is it only meant for open diffs?

I believe the open and viscous use different lengths of output shafts/flanges. The one side would probably stick out too far and the other may not engage properly. I believe you'd need the open outputs.

I never got an answer from OBX on which it was supposed to fit, but the flanges line up flush with my housing on both sides.

[trsilvias13]

How much did you pick this up for?

I know the guys at obx. He was talking about this lsd, he actaully told me the design and what was copied to make this lsd. I have to ask him again becuase I wasnt sure what he was saying because I was 1/2 asleep at the race track. He did say he did not get any returns on any lsd except for the first batch of lsd release for the honda's. On a side note, obx honda lsd help 660fwhp pulling in 10.3 in the 1/4 mile, and another 600+fwhp running 10.23 in the 1/4 mile over the weekend.


OBX also have ball bearing turbo coming soon too.

[240shorty]

It was 450 shipped (425 before), which was the price shortly after they came out. I have seen them listed for 385 plus shipping recently, so the price has dropped considerably in a short period. I suspect it will stay around that level as it is closer to the OBX diffs offered for other makes.

AFAIK, the only real gripe other than the usual 'you get what you pay for' is that the Hondas had problems with a non-beveled edge not releasing the half shafts. It may be worth noting that the 240 diff (and many other parts) market is grossly inflated in comparison to some vehicles. It is no doubt closely related to lesser demand and potential customer base. For a Mustang you can get clutch/locking diffs from reputable manufacturers for this same price range. Maybe cheaper. A decent diff CAN be produced in this price range. Quaife, Nismo, Kaaz, ATS, Cusco, *insert name here* have been able to charge overinflated (IMO) prices in somewhat of a niche market. Just because the price is less than half does not mean it is crap. Perhaps it means that the JDM companies and their retailers have profit margins that are too high.

As you may have guessed, I am not a JDM brand whore. I think the prices some people pay for name brand stuff is laughable, but it is their own money to spend.

Regarding the turbo. I think alot of people are hesitant to buy a turbo from a questionable manufacturer on the cheap. That is a whole nuther can o worms right there. I'll tell you I will not be the first on that bandwagon... especially considering the price of brand new Holsets.

[aznpoopy]

It could even be bushing related.

I could not give a complete review without including it though, as it may very well come from the rear. That is when I noticed it, so that's where I'd tend to attribute it.

subframe bushings
differential bushings
tranny and engine mounts
various suspension bushings

99.99999% of the time the biggest offenders are the subframe bushings. unless you've already put collars in.

how's the supercharged ka doing? got it running better? you haven't posted anything about it in a while.

[trsilvias13]

I will jump on the turbo bandwagon. They actually have better copying process than other supplier. Also the stuck half shaft problem have been solve after teh 1st batch. My friend who owns a honda was a test dummy for it and they found out threw him pretty much. My other friend with a mr2 will be testing out their greddy turbo kit.

OBX only made one original product and they were copied by apexi, so they stop doing r&d.

[240shorty]

how's the supercharged ka doing? got it running better? you haven't posted anything about it in a while.

Uhhhh... ummm... well... NO.

I know I haven't posted in that thread for awhile. That one I have been neglecting. Since you asked... I will update it now, but steel yourself, for you will not like the news.

[timtiminy]

what news are you talking about that we will not like?? news about the differential?? i really want to put one of these in my s13 for gripping purpose..basically will be building my car for grip handling and i feel that a torsen diff is the way to go, that and 17x9 tires, swaybars, poly busings, and coilovers. let the cat out of the bag and let us all know how the obx lsd is doing 240shorty! i know its dry now, and i'm sure you have tested the capabilities of this thing on a nice winding road.

[zads]

subframe bushings
differential bushings
tranny and engine mounts
various suspension bushings

99.99999% of the time the biggest offenders are the subframe bushings. unless you've already put collars in.


I have the S15 OEM Helical LSD (in a s13), stock engine/tranny mounts, aluminum subframe spacers, no differential bushings (s13 chassis), stock KA and oem-type clutch disk.

I also have the "clunk" you are talking about in the OBX. However, I did not check the backlash/tooth pattern on installation. Also, I have a full interior, and I can still hear it plainly.

I did have a ring gear bolt work itself loose as I was driving a couple nights ago though.. that was my fault, and damn scary :madfawk: Make sure you clean all the oil off your bolts before you apply loctite, and let it sit for a while before you add the gear oil.


I've flogged it plenty at autocrosses, and its very predictable.
4K rpm 2-step rev limiter clutch dropped launches (17x8, 235mm bridgestone potenza RE040 tires)? check.
You can powerslide it very easily.. open diff just made a whole bunch of inside tire smoke on tight turns.

[krustindumm]

OBX only made one original product and they were copied by apexi, so they stop doing r&d.

what was that?

[240shorty]

Zads: I did check the backlash and adjusted it for my install. I checked the tooth pattern with Prussian Blue. It was a little difficult to see and don't know why I checked; I never intended to adjust the pinion depth anyhow. Before I ever installed the diff I noticed that turning it around in my hands, you could hear/feel some internal parts move around and then stop. Something inside there has some free play. I'm sure it's normal, otherwise the diff would be thrashed by now. This is partly why I figured the 'clunk' diff related, as in the mechanical action inside the diff causing it. I don't think it is a product fault at all.

timtiminy: The bad news was related to another project (supercharger kit) that I had going. The diff is doing great.

I just finished my turbo install today. Only things left to do are plumbing in my BOV and splicing in one wire for narrow band O2 emulation. I'll update if anything breaks or with relevant info. Let the real testing begin...

[KuhnDawgAK47]

Just installed the obx hlsd into my s14. That clunk that has been disscussed doesnt happen in mine. I had a shop set backlash and preload and i have had no problems so far (its been in for a week). I have some more road noise but that is mostly due to subframe collars i added during the diff upgrade, but otherwise the diff is very quiet and doesnt bind up. It feels very strong, but i have yet to really launch the car, but hard cornering traction has been greatly approved the diff seems to be doing its job (but I'm no expert, my only comparison is to my open diff). Just thought I'd add my 2 cents.

[240shorty]

^ That is good to hear. I'll assume it's something else in my case then causing the clunk action.

I've got my turbo installed and running (finally). So the diff is seeing probably at least double the power to the wheels and still holding up fine. I have done some higher rpm launching. This thing gets you going pretty well. I think it will be capable of some pretty respectable 60 ft times with the right tires.

[AzNCmB]

I think it will be capable of some pretty respectable 60 ft times with the right tires.


well what's the hold up? get some good tires and give us some good 60ft times....:rolleyes:

[trsilvias13]

what was that?


some kind of adjustable exhaust silencer

[timtiminy]

KuhnDawgAK47 what did you pay for the diff install?? did you have the diff housing out of the caar or just take the entire car to the shop? giid ti hear that your happy. i'm just waiting to either figure out if im keeping my 89 hatch or getting a 91 before i do anything. i soo want to do this badly though, probably even before complete suspension.

[KuhnDawgAK47]

I paid a machine shop 100 bucks to cut me shims and set backlash with a dial indicator. I took the pumpkin out and brought the whole housing to the shop with the cover off and the oil completeley drained. The only thing you have to realize when doing the OBX lsd are the extra expenses (bearings, oil, shims) that you dont have to worry about with the kaaz and other setups. I ended up spending 600 bucks to do the whole swap.

[i8yourfwd]

That's including the diff correct?

[timtiminy]

KuhnDawgAK47 so you replaced the bearings with new oem, can you use your old bearings? what type of oil do you use..is it just regular sythetic motor oil for lubrication? i have heard you have to get the shims machined since no one makes them as thin as needed for this install...question, could you machine the diff and use thicker oem shims that are more accesible? you did the install yourself then, other than having the shims made?

[ryan hagen]

my s15 is loud, i set mine up for my required auto tech school differential rebuild and my lash and tooth pattern was good, mine with no interior in a s13 hatch and aluminum subframe bushings whinels like a mother fucker, you hear every noise that diff makes. you can hear all the heim joints move when i hit bump, diff is awsome but so much noise, rear seat is goin back in.

[RBS14]

you can hear all the heim joints move when i hit bump

Ummm. you must have some shitty heim joints then. You never hear good heims.

[240shorty]

Well, regarding any noise, I don't notice anything in the way of whining. It's not noisy in that regard at all. FWIW, I reused my bearings on my install and we're doing just fine.

Regarding those 60' times, I keep screwing sh*t up so I haven't been able to get to a strip or track. My recently turboed engine has low compression on 3 cylinders so I'm doing a quick build and swap to the spare. It is a better, lower mileage engine anyhow. I have launched the car many times now on the street and it does very well considering my crap tires.

[ryan hagen]

Ummm. you must have some shitty heim joints then. You never hear good heims.


gen1 powertrix, im siwtching to the teflon ones this winter.

[timtiminy]

does anyone know who distributes obx parts at a really good price?

[KuhnDawgAK47]

KuhnDawgAK47 so you replaced the bearings with new oem, can you use your old bearings? what type of oil do you use..is it just regular sythetic motor oil for lubrication? i have heard you have to get the shims machined since no one makes them as thin as needed for this install...question, could you machine the diff and use thicker oem shims that are more accesible? you did the install yourself then, other than having the shims made?


You could use the old bearings if they were in good enough condition and you wanted to save the money, regular gear oil for break in period and redline syn gear oil now, you cant machine the diff the bearings are flush with the lip on the diff shims are the only way to spec it properly, and i had the shop make the shims and just bolt the diff itsled back into the housing, i put the cover back on and put the diff back under the car. Sorry it took so long to repost I dont always recieve emails from zilvia, dont know why? Hope that info helps

[KuhnDawgAK47]

does anyone know who distributes obx parts at a really good price?

ebay is the cheapest way to get OBX stuff

[timtiminy]

okay well i was checking out a site that i figure we all may be able to get shims from. i was right they have shims pretty much a huge choice of sizes too. the site is www.mcmaster.com go down to raw materials and springs and click on shim stock that will bring you to a page where you can get pretty much any shim you could want. what size inner diameter and outer diameter did all you use for the differential install. I plan on doing my own install and i have never done it before i wouldnt imagine it being to difficult just make sure all the tolerances are to spec.

[timtiminy]

just wanted to let you all know that i bought a obx lsd installed in a s14 pumpkin, ill let you all know how it works out for me. Im doing a grip car setup. oh yeah i know i need to swap my s13 rear cover in oder for it to work on my s13 but is there anything else? an i was wondering if anyone knows of any aftermarket rear differential covers for the s13 diff? all i have seen is the s14 ones.

[Jung918]

Greddy makes them. I think Nismo might also.

[timtiminy]

have only found s14 rear diff covers from both those companys, i think that nismo made a s13 rear cover but i wouldnt know where i could find one. checked all the places that sell nismo parts and no luck. no other nissan rear diff cover is the same as s13 as far as i know? maybe i can modify an aftermarket s14 rear cover?? on a side note, just fixed my powersteering wow what a difference!!

[timtiminy]

just got the LSD in, it came installed in a s14 open diff housing, supposedly the transmission shop that installed it used new bearings and seals in the install, dont know if it is shimmed correctly or if it has shims at all. i think i will most likely pull it out of the s14 diff and install it into the s13 open diff i have. I will most likely pull all the bolts off the OBX LSD and red locktite them back in, its either that or i trust the install of the shop that put it in the s14 housing and just swap the rear cover. Tell me what you think i should do? oh yeah and what do i use for the bushings on the s14 housing to s13 subframe?

[trsilvias13]

z32 rear differ cover is the same as the s13 just to let u know.

[timtiminy]

actually it looks as if the z32 is the same as the s14 cover with only 2 bolts instead of the 4 bolts on the s13 rear cover. well i made up my mind on what i will be doing, looks like i will take the diff out of the s14 housing and dissasemble and make sure the washer set is installed correctly as i heard that this helps with preload and the sensitivity of the torque biasing in this diff. after that red locktite and torque down all the bolts and install into the s13 housing. hopefully the shims used when installed in the s14 housing will work for the s13 housing.

[99maxgtr]

hey guy's any info as to what size shims to get? i was looking at that size tim and i see that have the one where you can pretty much peel off the laminated cover to get the right amount of thickness now all i need to know is the innner and outside size? any help would be appreciated...the guy who installed this before just took out the shims to make it fit.

[timtiminy]

hey guy's any info as to what size shims to get? i was looking at that size tim and i see that have the one where you can pretty much peel off the laminated cover to get the right amount of thickness now all i need to know is the innner and outside size? any help would be appreciated...the guy who installed this before just took out the shims to make it fit.
Depends on what size you need, you have to check what the specs are and check backlash from there and figure out what size shims you will need. it is different for every diff. just make sure your tolerances are in spec with the FSM. P.S. where did you pick your diff up from? how much did it run you?

[99maxgtr]

picked it up on ebay. for about 420~ shipped.

[trsilvias13]

A little off topic, but I was thinking about getting a group buy status and get a group buy on this. Do you guys think there can be a market for this as a group buy? I can get it at a great price. If anyone local wants to pick one up. I am not a dealer or anything, but got hook up on this item and any obx item. PM if you guys like

[timtiminy]

I think there could be a good possibility that it would go well as a group buy.

I ended up dissasembling the diff, i rearranged the conical washers, there ended up being 8 washers instead of the 6 that i have seen people encounter in dissasembling the ones for fwd applications. i kept the 8 washers in there. the arrangement i used was ))(())(( and retightened the allen bolts to 20ft/lbs and went in a crisscross tightening pattern and used red locktite. everything looked really good when taken appart. i took pictures too so i'll post those when i get time. now i just have to get it shimmed up and in my s13 diff housing. I'll keep you guys updated.

[99maxgtr]

im sorry im a newb on this stuff but what is backlash and how do i check it?? and if i took this to a mechanic would they know what to do?

[addikted2bass]

:stupid:
message length

[!Zar!]

im sorry im a newb on this stuff but what is backlash and how do i check it?? and if i took this to a mechanic would they know what to do?
In a nutshell, it is the spacing between meshing objects. In this case, the ring and pinion. If they are too close, then you will have binding. If they are too far from each other, then you will strip the gears. So you can adjust the backlash with shims, and you can measure it with a feeler gauge.

Most knowledgeable mechanics can set backlash. Just take it to a reputable shop.

You can find the backlash spec thresholds in the factory service manual.

[timtiminy]

okay so after putting the diff into the s13 pumpkin and having the preload washers setup in the order ))(())(( now when i turn one wheel the other turns in the same direction, i thought that helical diffs act the same way as open diffs when one wheel is turned, that being the other wheel should turn in the opposite direction. perhaps the preload washers are tight enough to keep the two wheels together. i dont see it as a big deal, but should i be worried? havent put it on car yer

[IMPerfection]

subframe bushings
differential bushings
tranny and engine mounts
various suspension bushings

99.99999% of the time the biggest offenders are the subframe bushings. unless you've already put collars in.

how's the supercharged ka doing? got it running better? you haven't posted anything about it in a while.
My subframe collars introduced this noise to my car, and my symptons are exactly as the OP describes. I'm gonna presume its normal, since my car is bone-stock besides the collars.

[dans]

Update of OBX HLSD on isle 4 please.

[timtiminy]

yeah i would also like to hear an update. i cant wait to get mine going. i have it all together but i think i am going to hold off on the install until i get a new chassis and motor swap with full suspension. no ttoo far off from that though so, maybe by in the next few months. i created a huge amount of preload on the obx helical i have, which should solve the problem with full power transfer to lifted rear wheel. either that or it may cause problems i still need to figure out if as high of a preload as i have is good or bad on a helical diff, i dont want to hinder the proper functioning of the hlsd.

[naed240sx]

I'm not quite sure why you guys are adding preload to these diffs. The torque biasing ratio is set by the cut of the sun gears and planetary gears as well as what metals are used in the construction, the finish of the gears, and what oil is used.

Unless I am looking at this wrong, the only thing adding preload will do is to make the diff harder to turn.

Also, timtiminy:

You CANNOT fix the problem with lifting wheels. Any helical diff in any application will bias all the power to the lifted wheel because the lifted wheel has effectively 0 frictional force on it. You cannot produce a functioning helical differential with an infinate torque biasing ratio, so you can never overcome this problem, unless you have some sort of advanced traction system that senses such a problem in power delivery and applies some braking force to the rear wheels (Humvee's or Hummers(I can't remember which) have helical diffs and use such a system for offroading)

In the end though, it doesn't matter, because a properly setup rwd car won't lift either of the rear wheels when racing.

[timtiminy]

so why are they preloaded from the factory? when i put the conical washers in the way i did it made the wheels turn in the same direction when one is turned. i would think by doing this it would add intial torque resistance so if there is a 0 frictional force on one wheel there would actually be some frictional force because the diff is preloaded with this force. that way if i ever get in a situation (ice one wheel road other) i could actually get out of it. should i lessen the resistance of the preload because it may make it harder for the normal function of the diff to work?

[naed240sx]

Hmmm. You bring up a good point. How much force does it take to spin the wheels in opposite directions? I'm curious.

I have an s15 diff, and if I turn one of the wheels slowly with both off of the ground, they spin the same direction, but when I turn harder, the other wheel reverses direction.

It's obvious that you have increased the amount of friction inside of the diff, but im pretty damn sure it's not gonna be enough to allow you to get traction if a wheel is lifted, because the difference in the amount of torque created by a tire on the road, and the amount of torque neccesary to overcome the added preload is very large.

I think that by increasing preload, all you are doing is increasing the friction between the gears inside of the differential and their respective bearing surfaces. The only way that I can see for you to fix the problem with lifting a wheel would be to apply the ebrake in such a situation to generate an amount of torque at the lifted wheel.

The ice situation isn't really comparable to the lifted wheel situation. Are you worried about not being able to get moving from a stoplight or something? At it's worst, the helical will have as much grip as an open diff, so I don't think it's much to worry about.

[timtiminy]

well the diff is off the car, i just got it in the housing and the cover back on, havent put any fluid in it yet, i cant really turn the output shaft that hard or fast plus with no differential fluid in it there is alot more friction on those cone washers. I am wondering now if it is bad for the differential to have as much preload as i have on it. I have heard that with higher preload it responds quicker though, i just dont want to tear it all apart again to lessen the force of the preload. I dont think it will be too much of a problem, the worst that can happen is those conical washers could wear down from rubbing against each other, but even then it wont really cause anything adverse. check this out should be helpful if you don't completely understand what i am talking about.
http://rbryant.freeshell.org/obx_washers

[silnismo]

i know this was disscussed, but never reached an answer, Can a VLSD work with OBX HLSD? or does the VLSD have different gear ring & bearing? i am also deciding if i should get the OBX unit...

[naed240sx]

i know this was disscussed, but never reached an answer, Can a VLSD work with OBX HLSD? or does the VLSD have different gear ring & bearing? i am also deciding if i should get the OBX unit...

The internal dimensions for all R200 diffs are the same, except for minor differences like ring gear bolt diameter(s15 and r32 units use 13mm shank, 12mm threads bolts).

So to answer your question, yes it will bolt in. Problem will be with the output shafts. You can be pretty sure that they won't fit. You will need to get some open diff shafts to use with it.

Why not just leave it in the pumpkin, and sell/trade+cash for an open diff pumpkin?

[djsilver]

i know this was disscussed, but never reached an answer, Can a VLSD work with OBX HLSD? or does the VLSD have different gear ring & bearing? i am also deciding if i should get the OBX unit...

I had been wondering myself since I bought one without thinking to ask the question first. It's still in the box so I opened it up and checked today. The distance from the the bearing stub ends to the beginning of the splines for the output shafts is the same on both sides. That points me to the open diff output shafts since they are equal length. The VLSD shafts are unequal length, since one side passes through the spider gears to get to splines in the viscous coupling, which is off-center to the ring-gear side of the diff.

[silnismo]

The internal dimensions for all R200 diffs are the same, except for minor differences like ring gear bolt diameter(s15 and r32 units use 13mm shank, 12mm threads bolts).

So to answer your question, yes it will bolt in. Problem will be with the output shafts. You can be pretty sure that they won't fit. You will need to get some open diff shafts to use with it.

Why not just leave it in the pumpkin, and sell/trade+cash for an open diff pumpkin?

THX for the answer:kiss: But for some reason my VLSD that was equipped with with my s14 SE stoped working at 65,000 miles (partilly dued to driving in snow). Now it just works like a open but when i look under at the VLSD pumkin case it looks like maybe there could be a leak. you think if u change the viscous fluid, that by doing that might fix this???

[naed240sx]

THX for the answer:kiss: But for some reason my VLSD that was equipped with with my s14 SE stoped working at 65,000 miles (partilly dued to driving in snow). Now it just works like a open but when i look under at the VLSD pumkin case it looks like maybe there could be a leak. you think if u change the viscous fluid, that by doing that might fix this???

The viscous fluid in a viscous diff is separate from the rest of the differential oil. The viscous fluid cannot be replaced or refilled, becaue it is inside of the sealed viscous coupling. You can buy new ones from the dealer for like 600, but you would have to be an idiot to do that.

[turtl631]

I'll probably be getting one of these soon. Are backlash standards universal, that is, do I have to bring the specs to a shop or can I just show up with the open pumpkin and the new OBX unit? I'm hoping it'll be more in the $100-$150 range. My friend here in Atlanta got an S15 installed in a pumpkin for $200. That seems pretty steep considering the backlash on those is usually right at stock levels anyways! So just any transmission shop should be able to do this? Sorry about all these noob questions, I don't know anything about this stuff.

[naed240sx]

I'll probably be getting one of these soon. Are backlash standards universal, that is, do I have to bring the specs to a shop or can I just show up with the open pumpkin and the new OBX unit? I'm hoping it'll be more in the $100-$150 range. My friend here in Atlanta got an S15 installed in a pumpkin for $200. That seems pretty steep considering the backlash on those is usually right at stock levels anyways! So just any transmission shop should be able to do this? Sorry about all these noob questions, I don't know anything about this stuff.

When i was calling around about having my s15 diff installed, I called like 20 different general, gear and transmission shops. Nobody wanted to mess with it. The problem is, if a shop finds that backlash needs adjusting, they will have to order shims. It's not something that can just be done in a day, unless they happen to have tons of nissan diff shims laying around.

After researching and reasoning that since every oem r200 diff has pretty much the exact same dimensions, assembling like I dissasembled should be all that is neccesary to get a perfect fit, as long as the pumpkin that you are installing it into is in good shape and has not been tampered with.

I decided to do it myself. I used an r32 4.36 vlsd pumpkin. I removed the old diff, swapped the ring gear from it to the s15 diff, installed the s15 diff making sure all shims were in thier original places and bolted it back up. I did not measure backlash, but it felt exactly as it had when i had the vlsd in it. What i did do is get some gear indicator dye to check gear mesh. I got a perfect mesh pattern, and this was enough for me to know that it was about as pefect as it was gonna get.


However, since you plan on buying an obx diff, you might not be able to do this. Oem fits like oem, but you can't trust an aftermarket diff to do the same. I know kaaz diffs are close enough to bolt up, but I would never trust an obx diff. Either take it to a shop and eat a few hundred dollars, or be smart and get an s15 diff and install it yourself.


Edit: Didn't answer your first question. Backlash specs differ from manufacturer to manufacturer, and from different differential models. Of course all r200 diffs have the same backlash specs. When swapping in a new diff, you will want to make sure that the backlash spec is as close to the oem range as possible.

[turtl631]

Hm, so it might be more economical to pay more for an S15 diff and just drop it in than to get a cheaper OBX and end up paying for shims and install. I would do it myself but I don't have a dial indicator and stand, vice, bearing pullers...this is kind of out of the practical range of my apartment workspace. I'd rather have a used Nissan part than a new OBX one anyways; I guess this just seals the deal for me.

[naed240sx]

Hm, so it might be more economical to pay more for an S15 diff and just drop it in than to get a cheaper OBX and end up paying for shims and install. I would do it myself but I don't have a dial indicator and stand, vice, bearing pullers...this is kind of out of the practical range of my apartment workspace. I'd rather have a used Nissan part than a new OBX one anyways; I guess this just seals the deal for me.


Remember, i'm not saying that an obx wouldn't just drop in like oem. I'm saying that most likely you would have problems. What i do know is that i have never heard of anyone having to buy new shims for an s15 diff. As far as a bearing puller, you wouldn't need that because like 90% of the ones on ebay have the bearings already on them. As far as a dial indicator, yeah i looked into all that stuff myself. Decided not to fuck with it. I felt the backlash by hand before and after(yes this is extremely inprecise. However, it allows you to make sure that there is still SOME backlash, and that there is not a large amount).

I would say that if you are installing a quality diff (kaaz, tomei, etc) or an oem diff, and you check the gear mesh afterwards, the backlash is probably fine too. Just make sure that you do. Check gear mesh before and afterwards. If it is messed up to begin with, you might not want to use that pumpkin. Also, the only other problem with s15 diffs is the difference in ring gear sizing. If you are putting it in a standard s14 or s15 pumpkin you will need some .5mm wall thickness sleeves for your ring gear bolts. Apparently you can use ford starter bolt sleeves for this. I got lucky and didn't have this problem because i installed in an r32 pumpkin.


All in all, I make this sound complicated, but it's not. It goes in just like any other diff with the exception of the ring gear bolt size issue. Read the fsm about how to do it, and you will see that it is rather simple.

But yeah, used oem>cheap obx

[turtl631]

Yep, I think I'm gonna go the S15 route rather than deal with shimming. The OP noted that his had 0 backlash when first installed, so I doubt a straight drop-in is a good idea with the OBX. I'm tired of gambling on things and having them take forever to get right. S15 HLSD, J30 finned diff cover, and 4.36 ring gear for me.

[adamky]

Sorry to bump an old thread, but I'm new here and didn't feel like creating a new thread.

I just installed this diff tonight. Only was able to drive it for less than 30 minutes, but so far I like it. I tried dropping the clutch from a red light, and both tires began spinning and the rear stepped out to the side a little. Banged 2nd and there was no wheel spin at all. (Car is mostly stock, KA-T to come eventually.)

Also had a chance to take a really tight U-turn, so I floored it. The inside tire squealed but the car just kept pulling forward.

Concerning install... we were able to reuse everything and the diff dropped right in. Only hard part was the "snap rings" that hold the output shafts in. Those had to be removed from the open diff and placed in the new diff. This was quite difficult and time consuming, but there is probably a special tool that can really speed that up. Once we had them swapped into the new diff, the output shafts popped in easily.

The guy who helped me with this is a friend/co-worker who has done quite a few diff swaps in domestic rear ends. After dropping the diff in, we checked mesh pattern, and everything seemed good. He was very impressed by the size/beefiness of this "import diff".

Overall, I love this thing. Favorite mod to my car so far. Coming from an open diff, it's like a night and day difference.

[timtiminy]

thanks adamky. So what is the most noticeable difference that you had? most noticeable in handling, or off the line traction?
I specifically got mine for grip driving as i figured it would be best suited for grip. I can't wait to feel what it will be like getting on the throttle earlier coming out of corners and feeling the push of the rear end grip.

[kandyflip445]

Also, timtiminy:

You CANNOT fix the problem with lifting wheels. Any helical diff in any application will bias all the power to the lifted wheel because the lifted wheel has effectively 0 frictional force on it. You cannot produce a functioning helical differential with an infinate torque biasing ratio, so you can never overcome this problem, unless you have some sort of advanced traction system that senses such a problem in power delivery and applies some braking force to the rear wheels (Humvee's or Hummers(I can't remember which) have helical diffs and use such a system for offroading)

In the end though, it doesn't matter, because a properly setup rwd car won't lift either of the rear wheels when racing.


Use the e-brake.

[adamky]

thanks adamky. So what is the most noticeable difference that you had? most noticeable in handling, or off the line traction?

Both. It's like driving a whole new car. Floor it in first gear while turning, and you hear the inside wheel lightly squealing (crappy all seasons), but the car just keeps pulling forward like it doesn't notice. Drop the clutch from a launch, and both tires spin before it just grabs and goes.

Pulling through turns and accelerating out of corners is a blast now. Even with my crappy tires, the rear end stays pretty planted. I really have to try to break the rear end loose.

For grip driving or daily driving, a helical diff kicks a**.

[masterlocinc]

http://www.youtube.com/watch?v=R_Jb6jf3Bcg

OBX LSD in a S13, great for Drag and AutoX. Ok for occassional drifts but not for hardcore drifters.

[smelly240]

doesnt seem half bad - did you have it installed at a shop that does a lot of diffs? I wouldnt trust just anyone setting shims up and such.

[AceInHole]

I just rebuild my OBX diff. The belleville disc springs it comes with are crap.

Old spring stack:
http://i114.photobucket.com/albums/n247/AceInHole/PirateS14/OBX%20Diff/DSC_6192.jpg

Old vs new:
http://i114.photobucket.com/albums/n247/AceInHole/PirateS14/OBX%20Diff/DSC_6200.jpg

I'm almost done rebuilding my rear end, so I should have some input on my rebuilt unit soon. With the spring stack shot, it worked just fine, but a bit more noise than I like (engaging and disengaging). It managed to operate very well, planting 350'ish rwtq to two 315/35/R18's.

When I rebuilt it, I added a lot of preload to the spring stack, which should allow the diff to "engage" with the inside tire nearly unloaded. I'm just hoping it doesn't act too much like a phantom grip, locking the wheels too much, as it's extremely difficult to spin the output shafts in opposing directions as it is. After some testing I might pull it and rebuild it again, though. I've got more 1.250" OD bellevilles coming in in different heights/ thicknesses.



As for diff re-shimming, I'd honestly recommend doing so whenever replacing a diff, especially if you're running a decent amount of power. It shouldn't cost you more than an hour of shop labor from a competant transmission shop.

[drift into a curb]

Hey Ace, sorry to be a noob about rebuilding it, but I don't get any of the technical jargen in the FSM about diffs and such. Could you do a write up if you decide to rebuild the obx again? I'm running a clutch type personally, but I'd be interested to see how to rebuild the helical for future and i'm sure alot of the 240sx community could use your knowledge and know-how regarding this.

Thanks in advance!

[AceInHole]

Hey Ace, sorry to be a noob about rebuilding it, but I don't get any of the technical jargen in the FSM about diffs and such. Could you do a write up if you decide to rebuild the obx again? I'm running a clutch type personally, but I'd be interested to see how to rebuild the helical for future and i'm sure alot of the 240sx community could use your knowledge and know-how regarding this.

Thanks in advance!

A couple people have done extremely detailed OBX diff writeups. I believe there's at least one on HybridZ and a few on Honda-Tech.

For the most part, it's simply chasing threads, cleaning out debris, and rebuilding/ replacing the belleville spring stack. There's quite a bit of debris out of the box, and more after a few thousand miles of break-in. The spring stack is probably the thing you want to pay most attention to, as they've been notoriously weak. It's a quick fix if you do it before installing initially, as you can order a bunch from McMaster-Carr at between $5 - $7 for a pack of 12.

[adamky]

doesnt seem half bad - did you have it installed at a shop that does a lot of diffs? I wouldnt trust just anyone setting shims up and such.

I know you weren't directing that at me, but I'll answer anyways.

I installed mine with the help of a good friend. He's an older guy, and has put many diffs in domestic cars. We reused the stock shims exactly as they had came out with the old open diff. We checked the tooth pattern on the ring gear, and used a dial indicator to check backlash. Everything looked good. SO, it was basically a drop-in installation for me. (I did remove the allen bolts holding the diff together and reinstalled them with Loctite Red, but I did not mess with the internal parts of the diff at all.)

I've been running it daily for almost 3 months now and no problems yet. (knocks on wood)

[smelly240]

i meant - that you had an experienced person helping you (at least with advice) - you know checking backlash and pinion depth...

dont take it the wrong way ;) -- i didnt mean for it to sound like a slap in the mouth -

[adamky]

Didn't take it the wrong way at all. :) I was just answering your question.

[95KA-Turbo]

I understand this is an old thread. Just curious how the diffs are holding up for the people who have been running them for a year or so now. I got a lot of good info out of this thread, and I'd just like to hear how things are going at this point.

[Shift_Dr1ft]

Didnt want to revive an old thread but I was wondering where you guys bought the OBX lsd at? I check their offical site and found nothing. They have them at ebay but I dont trust ebay...

[i need tires]

im curious to know how these are holding up also! :mepoke:

[timtiminy]

well just to let you all know, me and my dad bought one for his celica and since it is made for the MR-2 is didnt have the slots in it necessary to put the speedo gear on it so we took it to a machine shop to have it machined and they couldnt even do it because the material they use is really hard. I would say thats a good thing that the materials they are using in their diffs are really strong. anyhow to make a long story short we ended up going with a TRD lsd for his celica gt-s, waiting to install it which i am excited about cause its already a fantastic handling fwd car and the tourque biasing differential should only make it better.

[On2]

Don't mean to dig this up from the dead but any updates on these? Thanks.

[Teambadrun]

Pictures??

[timtiminy]

seems like everyone that has installed them hasnt had any problems and likes them this far... I have one but have yet to put it on a car as my s13 caught fire and i think i set the diff up incorrectly so i am going to take it apart and redo it and get new bellville washers while im at it.

[On2]

seems like everyone that has installed them hasnt had any problems and likes them this far... I have one but have yet to put it on a car as my s13 caught fire and i think i set the diff up incorrectly so i am going to take it apart and redo it and get new bellville washers while im at it.
where are you getting them and how do you know how many to put in?

[timtiminy]

A couple people have done extremely detailed OBX diff writeups. I believe there's at least one on HybridZ and a few on Honda-Tech.

For the most part, it's simply chasing threads, cleaning out debris, and rebuilding/ replacing the belleville spring stack. There's quite a bit of debris out of the box, and more after a few thousand miles of break-in. The spring stack is probably the thing you want to pay most attention to, as they've been notoriously weak. It's a quick fix if you do it before installing initially, as you can order a bunch from McMaster-Carr at between $5 - $7 for a pack of 12.
Look up... its pretty straight forward. I know a guy that sells them the correct size but you can just get the measurements off the ones you remove and order them up from anywhere that sells them. just take the diff appart and take out old ones and install new ones, reassemble and you're done. i believe the correct order off the bellville washers for the OBX r200 lsd is ))))(((( . good luck with your diff. post up any more of your questions or experience with installing or using.

[JDS Performance]

Any good performance updates on this diff swap?
Like drifting - autoXing - draging it all day - basically getting it good and hot.

I have a buddy interested in a new diff and this looks promising...

[SuicidnS13]

Bump for updates from users with some decent mileage on these diffs...

[jamg]

bumping for more updates.

so anything new?

I just found out about this

[Reece]

bumping for more updates.

so anything new?

I just found out about this

Nice job at bringing up a 5 year old thread.

[dorkidori_s13]

Nice job at bringing up a 5 year old thread.

to be honest, ive been looking for information on the OBX helical diff as well and this is quite possibly the best thread ive run across so an update so many years later would be welcome!

so in otherwords, resurrecting this thread and getting an update would be well worth the zombie digging! :cops:

[VlaDeMaN]

rise, RISE my pretty!

so any updates from ANYONE running this?

[e1_griego]

I don't see the point of running this over s15 oem helical for almost the same price.

[VlaDeMaN]

I don't see the point of running this over s15 oem helical for almost the same price.

i don't remember where i saw this, but the OBX and quaife have higher torque bias ratios than the OEM helical. meaning they transfer more power to the wheel with most traction with respect to the wheel without, versus the OEM

look at this (scroll down to post 18):

http://forums.nicoclub.com/contest-find-me-the-torque-biasing-ratio-of-an-s15-hlsd-t168861.html.

[zeitgeist]

but from what I understand the OBX works with open diff output shafts. With the S15 helical you have to first source them and then pay a good chunk of cash. Seems like youd be spending alot more than 450-500 bucks
correct me if im wrong


i don't remember where i saw this, but the OBX and quaife have higher torque bias ratios than the OEM helical. meaning they transfer more power to the wheel with most traction with respect to the wheel without, versus the OEM

look at this (scroll down to post 18):

http://forums.nicoclub.com/contest-find-me-the-torque-biasing-ratio-of-an-s15-hlsd-t168861.

link doesnt work for me

[VlaDeMaN]

word, i left out the .html

http://forums.nicoclub.com/contest-find-me-the-torque-biasing-ratio-of-an-s15-hlsd-t168861.html

but from what I understand the OBX works with open diff output shafts. With the S15 helical you have to first source them and then pay a good chunk of cash. Seems like youd be spending alot more than 450-500 bucks
correct me if im wrong




link doesnt work for me

[dorkidori_s13]

I don't see the point of running this over s15 oem helical for almost the same price.

from what ive read, the s15 used a very specific output shaft setup (it was like 29 spline vs the s13/s14 28) and you have to use said shafts otherwise youll strip the shafts.

the OBX units seems to be a quality piece outside of some internal washers that are fairly easy to replace.

[e1_griego]

You buy a helical with the output shafts on ebay for like $550 and you're done.

You can't put 29 spline shafts in the helical anyway, and there's nothing to strip. Some people choose to buy the 13mm shank nismo ring gear bolts but you can just reuse the oem 12mm ring gear bolts and it's fine. I've done three different diffs with the stock ring gear bolts and never had a problem.

[zeitgeist]

i stand corrected

[e1_griego]

http://www.ebay.com/itm/JDM-Nissan-S15-Silvia-Helical-LSD-S13-S14-RB20-SR20-differential-rear-diff-/141202483879?pt=Motors_Car_Truck_Parts_Accessories&hash=item20e052eaa7&vxp=mtr


Or hit up ebay seller duax_machine as he usually has one or one on the way. He's out of texas iirc. I picked up one from him a couple years ago, and he's still an active ebayer.

[badbob2121]

You buy a helical with the output shafts on ebay for like $550 and you're done.

This is what I did when I bought my S15 Helical, I think I paid just over $500 and it was at my door step in 5 working days from Japan. Just put it on your tab at Harry's :bow:

[dorkidori_s13]

You buy a helical with the output shafts on ebay for like $550 and you're done.

therein lies the problem. you have to trust that they got the correct ouput shafts with the diff when it was pulled from the car. most of these importers dont know shit about what theyre importing and dont actually pull the parts themselves. if the output shafts dont work, then youre stuck with a diff that is useless until you can source the proper S15 output shafts, and if you havent noticed, those arent exactly the easiest of things to come by.

the OBX unit works with open diff shafts which makes life for damn near all of us S13 owners a lot easier!

[e1_griego]

I've never gotten one with the wrong output shafts. And duax_machine knows exactly what's up regarding the s15 diffs.

If you're using paypal and ebay, you shouldn't have an issue.

Drivetrain parts from OBX just doesn't sit well with me. If you want to do that, do it, but it's within spitting distance in price for OEM stuff.

[The Dude]

I rolled the dice and bought one of these probably about 2 years ago. Took the shitty washers out and replaced them with non-broken ones, did a little deburring, and also some thread chasing was necessary. So far so good. However, I paid quite a bit less than what I'm seeing them going for now. I would buy S15 helical unless you can get a good deal on an OBX unit and you aren't scared to rebuild it and make your own shims.

[Future240]

You buy a helical with the output shafts on ebay for like $550 and you're done.

You can't put 29 spline shafts in the helical anyway, and there's nothing to strip. Some people choose to buy the 13mm shank nismo ring gear bolts but you can just reuse the oem 12mm ring gear bolts and it's fine. I've done three different diffs with the stock ring gear bolts and never had a problem.

I am also resusing the oem 12mm ring gear bolts. Went in just fine. that was almost a year 30k+ miles ago, not a single issue.

[dorkidori_s13]

i reused my OEM ring gear bolts when i put my ATS 2 Way in my first 240. ran around on them for almost 100k miles with zero problems. just gotta make sure you re-coat them bad boys with loctite!

[dorkidori_s13]

site for OBX fixes...

http://rbryant.freeshell.org/obx_washers.htm

[jamg]

any more user reviews?

[Future240]

site for OBX fixes...

http://rbryant.freeshell.org/obx_washers.htm

The fact this site exists should say to everyone nix the obx and get an S15 HLSD if you want a torsen diff.

[Corbic]

i reused my OEM ring gear bolts when i put my ATS 2 Way in my first 240. ran around on them for almost 100k miles with zero problems. just gotta make sure you re-coat them bad boys with loctite!

Have you drifted on it?

I really can't find solid non-fanboy reports of how it does drifting. I'm a 2 events a year kinda guy, not a pro am wannabe.

My welded is driving me nuts with the tire eating and highway death wobbles.

I'm also not keen on dropping $1,400 for a clutch type.

[JSimpson]

Have you drifted on it?

I really can't find solid non-fanboy reports of how it does drifting. I'm a 2 events a year kinda guy, not a pro am wannabe.

My welded is driving me nuts with the tire eating and highway death wobbles.

I'm also not keen on dropping $1,400 for a clutch type.

You ought to hit up Mike at THmotorsports for an ATS clutch type. He hooked me up with a brand new one shipped straight from Japan next day air for a price that you wouldn't pass up. Comes with new seals and bearings/ races too. ATS is the shit.

[e1_griego]

Giken is the answer.

Corbic, arne't you posting in the DIW thread all the time yet you're rocking a welded diff?

Tsk tsk.

[bataangpinoy]

You ought to hit up Mike at THmotorsports for an ATS clutch type. He hooked me up with a brand new one shipped straight from Japan next day air for a price that you wouldn't pass up. Comes with new seals and bearings/ races too. ATS is the shit.

I have a Carbonetic Carbon in an s14 pumpkin that I'm willing to part with.

[dorkidori_s13]

Have you drifted on it?

it ran with me thru probably a good 20-30 events in its life time while i had it. locked up just as tight when i sold it with my last 240 (#4) in 2009 as the day i put it in my first 240 in 2004.

as far as drifting goes on a helical diff, mine worked just dandy on saturday when i took the girl im seeing out drifting for the first time. it didnt push quite as hard as a clutch style diff, but it did just fine! i wouldnt trade it for the world :kiss:

[dorkidori_s13]

The fact this site exists should say to everyone nix the obx and get an S15 HLSD if you want a torsen diff.

theyre not quite as bad as they seem. took some friends of mine here in town about 2 1/2 years to nuke the one in their track only 10 second EG civic hatch.

though i would highly recommend quaife over OBX any day. the quaife torsen diff is damn near the same thing as the S15 helical, but it works with OE 6 bolt open diff shafts as well as OE 5 bolt shafts too.

[Corbic]

Giken is the answer.

Corbic, arne't you posting in the DIW thread all the time yet you're rocking a welded diff?

Tsk tsk.

Balls of Steel bro.

It's actually not as bad as people make it out to be. Not much different then a locked spool. The only issues is tire wear and instability over 65mph on anything on than than marble streets.

DIW would be rocking the open or trying to JB Weld the open ^_~

[e1_griego]

I've driven 2 welded diffs in my 10 years and some change of screwing with 240s and I hated both. A lot.

I pray at the altar of OSG.