Shimming an R200 or J30 vlsd
 

By: Hunter Rodziczak

I could not find a comprehensive guide to doing this, So I thought I would make one for the good of the S chassis community.

Benefits: Get clutch type lsd action for a 1/4 of the price.

Well post j30 VLSD installation I found myself quite unsatisfied with the performance. As with Many VLSd's after becoming heated up they simply refuse to work properly and your VLSD becomes a one tire fire and thats no good. So after looking for upgrades I stumbled across a few options. Since I have a J30 vlsd with 5 bolt output shafts I would have to switch back to the standard 240sx R200 differential housing in order to run a clutch type lsd. I sold my old diff and a clutch type lsd wasn't in my budget. Somehow I stumbled across Shimming. Shimming involves adding an extra shim(s) to the original preload shim and causes the vlsd to lock similarly to a clutch type lsd. This preload shim costs $10 from you local Nissan dealer so this is definitely worth the money.


-Add one shim and vlsd will act similarly to a 1.5 way lsd

-Add two shims it will act like a 2 way/welded diff.

Here is a picture of the Shim with part no: ( this fits both j30 and R200 diffs)
http://i138.photobucket.com/albums/q...14/new5013.jpg
Here's your standard diff, Start By removing the diff from the car and unbolting the 8 bolts holding the diff cover on.
http://i138.photobucket.com/albums/q...14/new5001.jpg
Once that is completed, separate the cover like so and before you put the new sealant on remember to scrap off all old sealant and I recommend using brakecleen to clean surfaces before applying sealant back on.
http://i138.photobucket.com/albums/q...14/new5002.jpg
This is what you'll see:
http://i138.photobucket.com/albums/q...14/new5003.jpg
Next before anything else knock out the output shafts. This takes quite a bit of effort but don't be scared they will eventually come out. I recommend hitting them from behind with a hammer:
http://i138.photobucket.com/albums/q...14/new5005.jpg
Next you can take off the cap bolts like so:
http://i138.photobucket.com/albums/q...14/new5004.jpg
IMPORTANT: Remember which side the shafts and caps cam from as to not mix them up
http://i138.photobucket.com/albums/q...14/new5006.jpg
And this is what you're left with:
http://i138.photobucket.com/albums/q...14/new5007.jpg
Next, it's time to pry out the differential. Unless you have superhuman strength you have to get it out using a bar that give leverage:
http://i138.photobucket.com/albums/q...14/new5008.jpg
And end result:
http://i138.photobucket.com/albums/q...14/new5009.jpg
Unless you have a very good impact gun the next part is almost impossible. Take these bolts out to separate the ring gear from the diff.
http://i138.photobucket.com/albums/q...14/new5010.jpg
Next take off these two Phillips head screws.
http://i138.photobucket.com/albums/q...14/new5011.jpg
Pry apart:
http://i138.photobucket.com/albums/q...14/new5014.jpg
The Almighty shim:
http://i138.photobucket.com/albums/q...14/new5016.jpg
Now take this and put it over the existing shim:
http://i138.photobucket.com/albums/q...14/new5013.jpg
And now put the diff back together the same way you took it apart.


Impressions: Awesome locking compared to the stock vlsd can't complain.

Here goes another link also:

http://www.d1nz.com/forum/viewtopic....561d68f2602e75

i think this is one of those things that makes perfectly clear forehead-slapping sense once explained to you..

..but for some reason just did not even cross your mind ever before.


shimming a stock diff ACTUALLY works. duh.




so yeah, i feel stupid, but i'm glad you're intelligent. just wanted to say how cool i thought this write-up was.

Thanks man,

archive fact worthy?

sweetness, now do you have to measure/do the backlash?

if so anyone got a link lol

I was under the impression that our gear lash was set with washers? Do you have to change their configuration?

nope no changes need to be made

This works good, I had two friends do this 3 weeks ago

Aren't you just causing the gear engagement between the spider gears in the diff to be more heel/root heavy and therefore bind up?

I don't see how this is an "awesome mod." You're just incorrectly adjusting spider gears. Once you get a gear incorrectly adjusted like that, there will be relatively movement between gears as they mesh, which will wear them down in short order. Wear in a diff means metal shavings, which will cause accelerated wear in other components and potentially massive failure.

well in that case dont drift or drive your car hard because your wearing it faster, inevitably causing your vehicle to fail..

btw im one of the people that shimmed my diff about a month ago and it is still fully locked and feels amazing

how is a shimmed vlsd for daily driving? I'm getting sick of my welded diff since i only daily drive the car now, is it anything like a welded? Also, what are the long term ill effects of doing this to the diff?

mine is exactly the same as a welded, but i have a lot thicker shims in mine than a lot of the people who just add a small on to tighten it up a tad, in that case it would feel just like a normal vlsd that just locks easier

I added 1 shim a couple weeks and its pretty tight, mine had a ratcheting sound on slow tight turns, but after breaking it in and a lsd additive the ratcheting has almost gone but there is a ton more lock than i thought there would be. if i knew how much there would be i might have only replaced the shim other than adding 1. how was breakin for everyone else??? any noise or just some tire chirping??

can anyone list the part number cuz the pics arent working for me if its on there gonan do this asap very much hating on my vlsd right now

-Shims go up in 0.3mm increments from 0.8 to 1.49mm

38424-40F60 =0.80mm(same as in the picture)
38424-40F67 =1.01mm
38424-40F75 =1.25mm
38424-40F83 =1.49mm (the biggest)

Will this work with a stock open diff. too?

no

msg length

I thought the viscous diffs just had viscous fluid engaging the plates inside the housing, thus transferring torque between the 2 wheels?

If so, there shouldn't be spider gears turning and being meshed and destroyed, no?

wow this is awesome.. i have a vlsd lying around.. i need to do this before i throw it into my pumpkin.. nice...

bumping a good old thread..

just took my lsd apart, had a 1.25mm shim in there from the factory (odd) and I could only get a .80mm and a 1.01mm from nissan, i installed both of them... think its gonig to fully lock?

edit: Update...

here is a very easy trick that will save you a headake when installing the diff back into the pumpkin.

-lift the whole pumpkin up with all the bearings and spacers aligned. and drop it on the drive shaft end. ( a nice 1 foot drop)
-use a phone book or somthing to drop it on.
-the impact(s) will pull the lsd bearings and spacers all into place effortlessly.

(took me about 4 drops and i couldn't believe it was that easy. lol

first impressions.. (awesome) It was fully locked but i did a few figure eights and it loosened up a bit. feels perfect.... super tight.

^ you wanna help me do mine lol?

So I guess you can get buff while doing this too huh?

lol

The diff is like 100 pounds hahaha

i have this in my car as well.

best 4$ ever.

they're special order sometimes - i have an extra if anyone cant get a shim.

sure, pm me

Tourqe specs for ring gear?

hey my VLSd (I know for sure its lsd)dosnt work at all never has no matter what fluid i use... So do you guy think i should just get the biggest shim. Im doing this asap ill be waiting on the dealership im sure.

im all over this!!!

just wondering...
after shimming your LSD, does anyone get a slight whine/rolling noise from it? its not loud, but its definitely audible.

That whine/rolling noise is probably from improper gear mesh. I can't see how this is any good for the gears inside your differential.

for real though anyone got them???

impact wrench blast :P