S15 6 Speed Transmission for Dummies
 

S15 6 Speed Manual Transmission (6MT)

***Sorry if the photos no longer show up. Photobucket turned into a real shitshow of a site and wants me to upgrade to a $400 account. I'll figure out how to host them somewhere else.

http://i561.photobucket.com/albums/s...ver3/221-1.jpg
http://i561.photobucket.com/albums/s...ver3/222-1.jpg
http://i561.photobucket.com/albums/s...arver3/238.jpg
http://i561.photobucket.com/albums/s...arver3/240.jpg
http://i561.photobucket.com/albums/s...rver3/fsm1.jpg

Everything you wanted to know about the S15 6MT. A lot of this information is scattered all over the place. I'm just bring it together. I personally know quite a bit about the 6MT. I own and use two of them.

Please do not ruin this thread with a bunch of nonsense. Don't post information unless you are 100% positive that it is correct. Don't post how weak you think this transmission is, especially if you've never used or destroyed one yourself.. Any personal experience with this transmission is encouraged to be posted on this thread. For example, "XXXWHP and XXXWTQ, and I destroyed 3rd gear," or "XXXWHP and XXXWTQ, and she still kicks ass."

THE KA 5MT AND SR 5MT BELL HOUSINGS ARE NOT THE SAME.

I don't know everything, but I do know a lot. I'm not stubborn with what I am presenting to you. If you feel I posted incorrect or misleading information, I would be more than happy to hear you out and further research the issue.

To be covered:
- First look
- Comparison to the '5 Speed Manual Transmission' (5MT)
- Gearing and Specifications
- Gearing Comparison to the 5MT
- Necessities for Use
- VSS and Options
- Neutral Position and Reverse Switches
- Aftermarket Options
- Miscellaneous
- Final Notes
- Fitment on Other Engines
- Sources
- Post Notes

Pre-notes:
- I am strictly providing information regarding the S15 6MT for the SR engine. But, always take information as opinion anyway, and fact-check the information yourself.
- When I say 5MT, it is with assumption that it has a SR bell housing for the S13 and S14 SR engines and not a KA bell housing.
- When I am referring to a specific chassis, I will state so.
- I am strictly referring to OEM parts, excluding the 'Aftermarket Options' and 'Miscellaneous' sections.

Apparently the 6MT sycnromesh was designed by Borg Warner, just as the 5MT.
http://www.technolab.org/img/products/hako/hako1148.jpg

First Look
http://i561.photobucket.com/albums/s...rver3/fsm2.jpg

Nissan guarantees that this transmission will not fail at or below an input torque of 209lb-ft.

This transmission was designed with a Dual-Mass flywheel in mind. Watch this video for an animation on how the dual-mass flywheel works. The first half shows how it is assembled. The last half shows how it works.



Comparison to the 5MT
Similarities
- Bell housing pattern between the 6MT and 5MT are identical.
- The transmission mount is the same as the 5MT. However, the cross member is not the same.
- The slave cylinder, fork, pivot ball, release bearing, release bearing holder and pin all appear to be the same as the 5MT.
- The starters are identical between the S13-S15 SR engines.
- The 6MT clutch disc and pressure plate are similar to the 5MT. (NOTE: Because the 6MT uses a dual-mass flywheel, the OEM clutch disc is unsprung. The 5MT does not use a dual-mass flywheel, so the OEM clutch disc is sprung.)
- The output shaft to the driveshaft is the same as the 5MT.

http://i561.photobucket.com/albums/s...arver3/230.jpg
http://i561.photobucket.com/albums/s...arver3/232.jpg
http://i561.photobucket.com/albums/s...ver3/235-1.jpg
Starters may appear different, but seem to mount and operate the same.

Differences
- The 6MT flywheel is much thicker than the 5MT. Consequentially, the bell housing is also deeper by the difference in thickness.
- The copper pilot bearing is located in the 6MT flywheel, rather than in the SR engine for the 5MT.
- The 6MT is divided into three sections, rather than two for 5MT. So, no! You cannot put a KA bell housing on a 6 speed.
- The 6MT shaft is slightly shorter than the 5MT shaft.
- The shifter and shifter plate are not the same between the 6MT and 5MT.
- Shift knob threading is wider, but have the same thread pitch. 6MT = M12x1.25. 5MT = M10x1.25.
- The Vehicle Speed Sensor (VSS) is located on the differential rather than the transmission.
- The 6MT cross-member is opposite of the 5MT. (The AT cross-member is closer to the 6MT, but still will not fit.)

http://i561.photobucket.com/albums/s...ver3/224-1.jpg
Slight difference in spline thickness.

http://i561.photobucket.com/albums/s...arver3/310.jpg
Thicker Flywheel. (In this picture, both the OEM S15 Dual-Mass Flywheel and Autech Flywheel are shown.)

http://i561.photobucket.com/albums/s...arver3/307.jpg
This is the OEM Dual-Mass Flywheel with OEM Unsprung Disc and Pressure Plate. (If I recall correctly, the OEM Dual-Mass Flywheel weighs about 28lbs.)

http://i561.photobucket.com/albums/s...arver3/237.jpg
6MT Crossmember and Nismo Transmission Mount

http://i561.photobucket.com/albums/s...arver3/239.jpg
The 6MT bellhousing is noticeably deeper than the 5MT.

http://i561.photobucket.com/albums/s...arver3/241.jpg
The shifter plate and assembly are completely different.

VSS and Options
As many of you have heard, yes, the VSS is located in the differential, rather than the transmission.

Some of you have speculated that some 6MTs have a plug covering what looks to possibly accommodate a VSS. This is true and false. Yes, the whole is the right size and shape. No, because the plastic gear that turns the VSS is absent from the output shaft. One would need to purchase the plastic gear (and a steel ball and c-clips that lock the gear in place) and dissemble the transmission to install it.

Some 6MTs don't have a plug. They may be cast molded shut.

http://i561.photobucket.com/albums/s...arver3/243.jpg
http://i561.photobucket.com/albums/s...arver3/245.jpg
Here we see one 6MT has a plug and the other does not.

So what are the VSS options?
1) Purchase and install the plastic gear (as mentioned above) and use the pertaining S13 or S14 VSS. This only works if you have a 6MT with plugged VSS slot.
2) Install a differential that has a VSS in it. This is not limited to the S15 differential. From what I've seen, a Q45 differential has a VSS and may be used.
3) Custom magnetic pick up or gear tooth pick up and sensor attached to the driveshaft.

So what are the signal modifier options for the speedometer to read appropriately?
If option 1, then you won't need anything. If you're using a S13 cluster, then use a S13 VSS. Likewise for the S14.
If option 2, you can either use the S15 ABS control unit (located next to the ECM) or use an aftermarket signal modifier such as the Dakota Digital box or Innovate DL-32.
If option 3, you will need an aftermarket signal modifier.

Neutral Position and Reverse Switches
http://i561.photobucket.com/albums/s...gs156speed.jpg
Wiring the transmission to continue using the reverse lights is very easy. No explanation should be needed here.

Gearing and Specifications
http://i561.photobucket.com/albums/s...rver3/fsm3.jpg

Gearing Comparison to the 5MT
http://i561.photobucket.com/albums/s...rver3/fsm4.jpg
http://www.nissans15.com/img/autech%20gear%20ratio.jpg
http://img.photobucket.com/albums/v7...r/rpm-vs-v.jpg
http://img.photobucket.com/albums/v7...-rpm-NISMO.jpg
***This last one I estimated where the Nismo 6MT gear ratio would be. The original can be found below.***

Necessities to Use a 6MT
For the SR engine ONLY.
- S15 Transmission Cross Member. The 5MT and AT cross members will not work.
- Transmission Mount. The 5MT and 6MT mounts are all the same.
- 6MT Flywheel. The 5MT flywheels will not work.
- Clutch Disc and Pressure Plate. Any clutch kit for the 5MT will work, but if one is using the OEM S15 Dual-Mass Flywheel, then feel free to get an unsprung clutch kit, even though this may be costly. Sourcing a new OEM replacement clutch kit is rather difficult to find. You can use a sprung clutch kit on the Dual-Mass flywheel, but the dampening will be overkill and shifting between gears may feel sloppy.
- Clutch fork, Release Bearing and Holder, pins, and slave cylinder. I am not 100% here, but they appear to be the same between the 5MT and 6MT.
- Driveshaft with S15 output. (Unsure, but the OEM S15 driveshaft may be used as long as the S15 or similar differential with VSS is used.)
- Shift knob with M12x1.25 threading. The 5MT shift knob won't fit because it is thinner, M10x1.25.

Notes: It is best to install the transmission and engine together. With the 6MT mounted on the engine, it will not touch hit the chassis. But, because it is still fatter than the 5MT, there is less room to muscle the 6MT on or off with the engine already mounted. Don't forget, the flywheel is about an inch thicker, which means you need to pull the transmission about an inch further back. That's never going to happen... I've tried; there is no room for removing and installing the 6MT separately from the engine.

Everything else is straight forward and no different than the 5MT. Be sure to torque all bolts down to spec. They will shear if you over tighten them.

Parts to Reference
http://img.photobucket.com/albums/v7.../Partslist.jpg

Aftermarket Options
- Driveshafts. Driveshaftshop.com seems to be the place to go.
- Flywheels & Clutch Kits. This may get costly, but one can either source a used Autech flywheel (~$400), purchase a new JUN flywheel (~$700), or purchase a clutch kit that includes a new flywheel (~$1100+). The benefit of getting the Autech or JUN flywheels is that you can continue using a 5MT clutch kit, whereas a complete clutch kit such as the Nismo Coppermix may force you to stick with the same disc.
- Gears. Nismo, OS Giken, and possible others make gearing kits for this transmission. These kits are rated to withstand more power.
- Transmissions. Nismo and HKS make complete replacement transmissions. The Nismo transmission costs ~$3500, but only guarantees quality up to 298lb-ft. The HKS transmission costs ~$10500. Both, however, have different gear ratios compared to the S15 MT.

http://i561.photobucket.com/albums/s...8_36009628.jpg
Comparison between the Nismo 6MT, S15 6MT, and 5MT.

http://img.photobucket.com/albums/v7...rver/tran1.jpg
http://img.photobucket.com/albums/v7...rver/tran2.jpg
http://img.photobucket.com/albums/v7...rver/tran3.jpg
http://img.photobucket.com/albums/v7...rver/tran4.jpg
Here are some more individual comparisons.

Miscellaneous
- Nismo 6th Main and Cross gear swap
http://i7.photobucket.com/albums/y27.../build/036.jpg
I swapped out the 6th gear on one of my 6MTs for track use. It brought the gearing much closer to 5th. (Gear Ratio changes from 0.764 to 0.8624)

- Closer look at Autech Flywheel
http://i561.photobucket.com/albums/s...arver3/226.jpg
http://i561.photobucket.com/albums/s...ver3/227-1.jpg
http://i561.photobucket.com/albums/s...arver3/308.jpg
If I recall correctly, the OEM Dual-Mass Flywheel weighs about 28lbs, and the Autech Flywheels weighs about 17lbs. Also, the Autech flywheel was engineered by both Nismo and Exedy. Both of their stamps are on the flywheel. (The clutch disc pictured is the Fidanza 3.2 Clutch Kit).

Final Notes
Some of you guys jump the gun by saying, "forget the 6 speed, its weak anyway.." but most of you never used, touched, or seen a 6MT in your life. Don't continue making this your automatic response when the 6MT is mentioned.

How come this guy with 400WHP hasn't destroyed his 6MT when I only have 340WHP and destroyed mine in weeks???
Assuming you know how to shift, it just depends on two things.
- How much TORQUE are you putting out? Not horsepower... One guy may do 340WHP and have 280WTQ while another may have 340WHP and 320WTQ... (If the engine has a GT2871R, bigger intercooler, and injectors, then it should be fine. If you put a rebuilt the engine from scratch and/or put a 2.2L stroker kit, why didn't you buy a stronger transmission anyway? Even a 5 speed is a shitty tranny to mate with a built SR..)
- What are you using the transmission for? Drifting??? Drag???? This transmission isn't good for smashing gears like a mad man, especially with a very abrasive clutch. If you're engagements are smooth, the transmission will do fine. Most of you, and I mean 95% of you, aren't even close to 300whp. So destroying a 6MT transmission would be the last of your worries.

Nissan designed and guaranteed the quality of this transmission when torque input is no more than 209lb-ft. This is because Nissan (as well as any manufacturer) designed the transmission with a Factor of Safety or Margin. So, under normal conditions or even if one were to push an unmodified Spec-R to its limits, the transmission will not fail. (Assuming the tranny is well maintained.)

I estimate Nissan has a margin of AT LEAST 1.333, so one can expect an actual limit to failure to be a least 270lb-ft (emphasis on "at least", because I personally know someone with 270WTQ and has no problems what so ever). The gears are fragile to sudden impulses. To create an impulse, one could simply clutch kick or drop the clutch from a stand still, but you'd need some very sticky tires and a very abrasive clutch. If one were to transition smoothly between gears, no severe impulse made, and the oil used effectively fills the gaps between the teeth of the gears, then this transmission would be capable of at least 300WTQ. (These are all ball park estimates.) Anything after that, beyond me. Have heard of someone with 340WTQ and not having problems... but this is second/third hand information.

Keep in mind that the OEM S15 flywheel is a Dual-Mass flywheel. This flywheel significantly reduces an impulse, making engagement very smooth and allowing the gears to withstand more torque. The Dual-Mass flywheel is quite nice, especially with the unsprung clutch disc. I honestly cannot tell the difference between a dual-mass flywheel with an unsprung clutch kit versus a regular flywheel with a sprung clutch kit (aside from the difference in rev response). I think the dual-mass flywheel with, for example, with the Fidanza 5.4 unsprung clutch kit would be an awesome combination. With the OEM unsprung clutch kit, there is ZERO clutch chatter.

Fitment On Other Engines
- No.
Hahaha. This just isn't the transmission to bother with that. The amount of work it would take to re-center the input shaft of the 6MT to a KA engine, create a sandwich plate to marry the engine to the 6MT, make sure the clutch fork will pivot in the correct range to release the clutch disc, and align the starter to line up with the flywheel... you might as well do this for a sequential tranny, or some other heavier duty tranny.

Sources
- 1999-2002 Nissan Silvia S15 Factory Service Manual
- 1991-1994 Nissan 240SX Factory Service Manual
- Nissan S15 Specifications
- Octane Report - Nismo 6MT Conversion
- Dual-Mass Flywheel assembly and functionality - Youtube
- NISMO | Silvia•180SX Reinforced Cross 6-Speed Transmission
- Gearing and Assembly Prices and Comparison
- Parts List and Prices per Chassis

Post Notes
I think this transmission is a lot of fun to have, but not for drifting or drag racing. I use the transmission for road racing, and it has performed exceptionally well.

Again, please do not ruin this thread. Ask legitimate questions. Post solid facts and experience. If you have not used and/or destroyed this transmission, you're post/claim may not be valid to me.

Hope this helps a lot of you guys.

Good info! Thanks for sharing!

Thanks for sharing...

Amazing write up we don't even have this much info in AUS about the gearbox.

Thank You

Sent from my GalaxyS using Tapatalk

finally some reliable info... i was tired of just hearing, "those trannys are weak! just use a z32..." ghey...

Awesome write up! Always wondered about these nice little guys... I would love to have one...... Did you do the 6th gear yourself?

WOW, thanks for putting this out there in one place!!!

No problem. There are some details I left out. I'll add them whenever I can recall them.

Edit: Holy fuck... Completely misread your post.

Yes, I do have the Nismo 6th gear installed on one of my 6MTs.

Finally found the other graphs. These are much better illustrations.

http://img.photobucket.com/albums/v7...r/rpm-vs-v.jpg
http://img.photobucket.com/albums/v7...r/v-vs-rpm.jpg

Edit: I added a line for the Nismo 6MT in the original post.

THANK YOU! i just picked up a 6sp/s15 spec r motor and have been searching and searching for info. i do have a few questions for you though...

-do you know the part number or where to buy the s15 cross member?
-will the s13/s14 transmission mount fit on the s15 crossmember?
-does the 6spd use the same transmission fluid as the 5spds?

1) 3137S-RRS50

2) Yes

3) Yes

~~~~~~~~~~~~~~~~~~~~~~~~~~~

Added a lot more information. More gear ratio comparisons and sources to reference.

i seriously <3 this thread...like A LOT!!!

awesome find in information man, threads like this should be made PERMANENT stickies!!! (ill recommend it for one actually)

Great info, props yo
I think an S15 SR w/ 6-speed tranny and mild boost upgrades would
make a killer daily


btw, how is the hand?

Thanks :)

Hand is doing much better. It was a clean cut, so it healed very fast.

~~~~~~~~~~~~~~~~~~~~
Started using the dual-mass flywheel instead of the Autech flywheel. I must say, this flywheel is pretty cool. With the OEM clutch disc unsprung and letting the flywheel dampen the engagement, there is ZERO clutch chatter. I highly recommend it for daily driving. It may play a major roll in extending the life of your transmission.

If you increase your horsepower to +300whp/+240wtq and are still using the dual-mass flywheel, I would recommend the ACT 6 Puck unsprung clutch kit as a good replacement of the OEM unsprung clutch kit.

Thread stuck due to pure awesomeness.

dope ass post Joel.

i agree thread is overkill. haha.

Awesome! Thanks for the sticky Mark. :D

Wayne, Vatche, thank you too. :)

Great thread with great info! I have one of these bad boys if anybodys interested hmu!

No 6 speed to KA. You killed my dreams Joel. lol


Great tech thread. This is more of what Zilvia needs.

Really nice post. Had all the information I needed to hear. I am just curious..... if you have the time, you think you can research the HPI transmission? I hear that company took the NISMO tranny and made it stronger with less noise on the higher RPMs. I was reading it under RHDjapan.com.

Again, great job.

Oh, don't have a car yet but will be buying an S15 around April. Got to finish paying off debts first :). Driving a freaking Honda Accord for the time being just incase anyone was wondering what car I drove:(.

So to put a SR20DET from a S15 into a S13 would require a S15 transmission crossmember, driveshaft, and a way to get the speedo sensor to work? and of course all the other usual stuff. I have heard you can use the stock S13 Crossmember.

s14 slave cyl. works on a s15 as well. figured id add that since i just found out trying it myself

thanks for the goog thread

any options to tighten up the shifter? i know the hks springs arent compatible or the cusco shifter collar. are their any similiar options for the 6mt shifter? also, i noticed you said the oem clutch should be upgraded once you go above 300whp, but just how durable is it? i know thats a relative question but from what i gather you're still using it so i was just wondering for how long and what kind of driving you were doing with it?

I'm still not certain on the options to tighten/shorten the shifter on the 6MT. I've seen a few modified/aftermarket shifters on the Upgarage website, but there wasn't enough info in the ads for me to bother buying one.

I may have jumbled my words but generally speaking, the 6MT is going to fail due to an impulse/jerk. So, getting a clutch kit with harsh engagement, such as a hyper single, is going to significantly increase the odds of shearing teeth. This transmission can handle at least 300WHP, but if you're not smooth with your clutch engagements, completely letting off the throttle at 7500RPMS in second gear, clutch kicking like its 2012, then you're 6MT is going to fail. On full deceleration, the weakest gears are 1st-3rd, which usually fail at high RPMs. (The engine is trying to slow down while the momentum continues to drive the car forward. Bother gears become drivers, and you end up with two opposing forces that meet at the teeth in the transmission.) Clutch kicking with this much horsepower and very sticky tires will shear some teeth. Using the hand brake and powering the car through a drift should be fine. It's possible to drift, but generally its not ideal for +300WHP.

On my track car, I use the Autech (Nismo/Exedy) flywheel and a Fidanza 3:2 Clutch Kit. Been using this setup since 2009 and still have yet to replace the clutch. On my daily, I use the OEM Dual-Mass flywheel and an unsprung clutch kit (currently an OEM Nissan kit). The flywheel and clutch kit were used when I bought the swap, but I've added another 5000 miles to it and still feels great.

I use my track car for road racing. Currently, the engine is only doing 200WHP. I've fooled around with a friend's S13 with 6MT (270WHP and about 250TQ) and drifted around a few corners. Transmission felt fine. I believe he is also using the OEM Dual-Mass flywheel and an unsprung clutch kit (unsure of brand).

I try not to let the blonde come through to often, but reading this thread I so far only have one question sir.

on the graphs with grey and black lines, which one is the nismo gears and which one is the factory gears?

thank you, and I apologize if I missed that part.

Light Grey is OEM Transmission gearing. Bold Black is the aftermarket comparison.

How much to these trannys go for?

A bit hard to answer. Here in the state, they usually sell for $400-450 for the transmission alone. Maybe $1000 if the flywheel, clutch kit, crossmember, and driveshaft (new, steel) are included. But, I'm no one to say what they should cost. I'm just posting what I've seen them go for.

In Japan, the 6MTs still sell for about $650, but shipping is an arm/leg.

So im assuming people who run the 6MT never do upgrades there SR? I want to know how much power they can handle?

This is an excellent write up. I have a couple 6 speeds and I joined the forum to add one thing. In my S14 (not sure about S13 chassis) I can install the transmission separately from the engine. I need to disconnect all the intercooler plumbing and hoses and move the wire running along the top of the firewall. Doing those things allows the engine to tilt back enough to remove the tranny. It is a squeeze though.

found this while searching for the 6spd crossmember ala-carte:

http://www.nismo.co.jp/en/products/c...ilvia_spec.pdf

it contains all the part numbers for essentially anything 6spd related on the 180sx/silvia.

ALSO, be advised the throwout bearing is NOT the same between 5spd and 6spd. i don't recall off the top of my head but one is of smaller diameter compared to the other.

what an excellent and thorough write up, thanx man. Zilvia needs more of these!

Great info here guys. Im just curious why do you have to use the s15 flywheel when fitting the 6 speed to a non s15 sr20det?

I can understand the flywheel is thicker. Is the input shat on the 6 speed not long enough to work with the s14 flywheel?

has anybody put speedo drives in these? I have the nismo cross reinforced box which had provisions on the main shaft for a speedo drive, ie had the two grooves and hole for a steel ball with the rear housing having a removable bung over the vss hole.

i did a little tinkering myself..

i put a drive gear on the main shaft using an rb25 auto speedo drive gear. it is 2mm smaller in internal diameter. but very carefully i was able to bore it out enough just before the gear became too thin. it was also to wide to fit in the space provided. so i ground it down on a bench grinder and tidied it all up.

i will be using a c34 vss and i am hoping that it will do the trick. if not i will have to find myself a s14 vss.

have heard of people running s15 abs computer etc etc but too much of a hassle for me and i already took my abs out anyhow

big power
 

i have the s15 engine and trans and i am planning to make in the neighborhood of 550 to 600 hp max is there anything i can do to strengthen the tranny without spending $10500

The 6 speed gearbox uses same yoke as an RB auto box if anybody didnt realise this

Great thread. I had one in my non turbo S15 SR car and I never had to replace it. I beat the hell out of my S13 drifting as slow as I could, and the tranny never gave me shit. Considering about doing the 6spd MT in my S13 SR setup , but I have an FC..so it's complicated like a Facebook relationship status.

Shot in the dark, but I want to say it is bc both the flywheel and bell housings overall diameter are larger and the matching flywheel is needed for trans, flywheel and starter to align.

6 speed uses dual mass flywheel, needs it as stated above different diameter bellhousings etc

hello from chicago, i have a kinda silly question so please dont kill me,lol can the drive shaft from the 5mt s14 fit the 6mt from a s15? i have a s14 blktop with a 5mt and blew 5th gear and when i put it in reverse the trans wont go back to nuetral when i want to get out from reverse unless i drive it in rev, for about 10ft or so then it pops out on its own? so i just got a 6mt and now the driveshaft doesnt fit?so what should i do? im kinda lost here,anyone in chicago have a yoke i can buy for 6mt? lol hit me back.thanks and this wright up is SSOOO informative! thank you so much. [email protected]m

You can use an auto drive shaft. I dont know if it is the same as a SR auto. But in my 6 speed i actually used a factory auto drive shaft from an RB R32 skyline.

Basically the 6 speed yoke is just an auto yoke. everybody says u need a custom one blah blah blah. But no u dont. auto has same yoke.

hello again, hey 3v1ls14 thanks for the reply. but i still have a problem, i cant find any skyline parts locally and would have to order from somewhere online,so what other options do i have for a driveshaft yoke for the 6mt? can any other yoke fit from other us spec nissans? i've been hitting the junkyards for about 3 days now and no luck. :( i thought a ka yoke would fit but none available what would be best for my trans/yoke combo? or do i need to have a custom yoke and d-shaft made? im stuck!! lol any one else care to share as well please, thanks very much. oh btw, pics to come soon, i have a 1977 corolla wagon(te38) with s14 sr20det and ae86 gts diff. so hopefully can take her out soon, thanks again forum.

any nissan rwd silvia skyline etc auto drive shaft yoke fits the 6 speed!

will a 5 speed from a KA fit on a s15 motor?????!?!?!?!?!

This maybe a silly question, but do you think that there is a possibility of removing the bell housing to machine off the extra thickness and run an s14 flywheel? Or since that might misalign the starter, take the bell housing and section an inch out of it at the base which would pull the tranny closer without messing with the starter aliment. I think I'm going to try this and get back to this thread to report my findings because a 17lbs flywheel is just unacceptable when with the s14 setup you can have a 9.5lbs flywheel.

Great info thank you

I would not recommend this. The transmission casing is made of cast aluminum, and you may weaken the integrity of the casting, which may lead to cracking.

An easier solution would be to use something like the Exedy hyper single. The included flywheel is not dual mass and extremely light comparatively. Also I can second the other S14 owner. Removal of the tranny alone is doable in an S14 chassis, it's a pain though.

its taking a box out of a car while still in place. it is what it is. not usually very fun to do and you will more than likely have a little less space than you'd like, but you can do it if you feel like getting it done.

No, the distance needed to clear a dual mass flywheel is much larger, you can find aftermarket 6MT flywheels that are the proper distance.


The distance you would have to cut the housing down would surpass the alignment holes, not to mention its extremely unsafe idea in general.

thank you for this thread !

so i figured this would be the best place to ask

i got a 6 speed swap and is came with this was told its a nismo flywheel its very light

thinking its the Autech Flywheel

anybody can confirm this and maybe have more info on it as of it value
i searched for a little and could not find much on it
http://i157.photobucket.com/albums/t...045F3221B0.jpg

where could i possibly get a rebuild kit for a 6 speed?

Did you blow up gears or are you looking for synchros? If you blew up gears, the cheapest option is to find a replacement trans or go 5-speed. I'm unsure where you would get a rebuild kit for synchros, I've always assumed they are only sold in Japan and would probably cost too much anyways.

Your post did not answer my question in any way.. Not looking for gears, looking for a rebuild kit(seals, syncros etc)

Sorry man, wasn't trying to help you or anything. I've looked for the same thing a while ago, and with little information on the 6-speed I couldn't find where to go. Previous post was kinda hinting that you're on a lost cause. If rebuild kits are only sold in Japan, (which I think they are) then you have to find a seller, convert yen, pay shipping, rebuild at a shop. In all, it'll cost less than a 5-speed swap. Makes no sense to do all of this work on a "weak" transmission, but that's a whole other case.

GL on finding info, post it here if you do.

Did you read this thread?

great info!! wish there were more threads like this

Did you? Its a been a while since I've looked for this stuff.

This is not a thread for ppl to request info and other ppl to say "just get a 5sp" ... This is the 6 SPEED INFO THREAD. Meaning if someone asks a question and you don't have the answer, "just get a 5 speed" is not the right response. And for your info, I have a six speed already.. Sorry you didn't.

Don't be a chode, sit back and relax, no one is knocking you. You misunderstood my intention to gain reason out of you. Do what you want, you are gonna be terribly butt hurt when you find the price differences to rebuild a 6 speed compared to a 5 speed. When you find a place, share your info. I had a friend in Japan check years ago and it was laughable when you convert yen and add shipping. I honestly have no idea where you can find rebuild kits for 6-speeds in the states. Try calling Touge Factory?

for anyone wanting a complete 6 speed swap

#/f/sale-items/51031...o-dss-s15.html

-I previously had an s15 engine/tranny with nistune/cams/injectors and dyno'd 303whp and 304wtq.
-16lbs boost stock turbo.
-tuned by Martin from Zfever in Tampa, FL.
-The 6 speed handled the torque no problems.
-Never drifted but did go to drag strip 3-4 times with about 3 passes each time.
-Minor issue of getting into reverse, but resolved issue with solid tranny mount.
-car was stolen Oct last year
-Loved the trans so much decided to mate it to my l26 in '74 datsun Z

-If you want to see my build thread on the old fairlady type
"s30 with s15 6 speed" into google

-Should be finished with build in mid May this year.

-Dont bash this Trans unless you bash gears!

I said I was going to do this last year and I have. I've successfully shortened and mated a six speed trans. to light 17lb clutchmaster fx700 clutch for all other sr's and I've found out some interesting things while doing it. The people who think that the six speed is weak have no idea what their taking about. I had both 5 and 6 speed tranny's apart and sitting side by side. The truth is that the gears are the same size. The only reason people think the tranny is weak is because of the behemoth of a 40lb dual mass flywheel in front of it. It's simple physics, take a 40lb rotational mass spinning at say 5000 rpms and then try to slow it down with one transmission gear, say 2nd and what do you get, no 2nd gear. The reason the 5 speeds hold up to the abuse better is quite simply due to the light weight flywheel's available to it. I solved this problem and I'm going to make more if anyone is interested. I'll be selling them on eBay in the coming months so stay tuned. Mind you it's no easy task and requires a lot of calculations to make it right, but when it's finished you can mate the 6 speed tranny to any sr20 clutch available. I will upload some pics once I get back home to my computer.

no.

No.

You're wrong.

So you created a flywheel shim?

And no.

Thank you for the info in this thread, it's actually funny how similar this trans is with my G35 (350Z) 6mt. Dual mass flywheel, etc.

Waaaay back in 2001-2002 timeframe, when I was working on my first SR swap, somebody somewhere busted his 6-speed and the "weak" rumors seem to have been parroted by forums ever since. Plus S15 swaps were $7-8k back then so "too expensive" also came into play.

Recently got another 240, glad to see things have progressed since 2005.

dam great job on the post

No shim idiot, obviously you no nothing about this trans. You can't shim a flywheel out and still have your starter engage the ring gear. I physically shortened the bell housing and relocated the pilot bearing into the end of the crankshaft. I have had these transmission completely apart and sitting side by side and I'm telling you the gears are the same size. The 6 speed is 5% narrower and that's it. It's the inertia of the flywheel that snaps gears. Instead of the load being transferred back into the motor and bogging it down, it simply keeps spinning and strips off gears in the trans. It's simple physics. You haven't done it and you don't know, so stay off this thread, negative Nancy.

^^^LOL this faggot

Here are some pics I took of the transformation.

Attachment 56674New pilot bearing in the end of the crank shaft, relocated from the flywheel. The input shaft is not long enough to locate the pilot bushing in the standard location inside the crankshaft. Pilot bearing is something we found at the local bearing shop.

Attachment 56675 Mocking up the transmission without the bell housing to figure out the amount that needs to be removed.

Attachment 56676 No going back from here. Cutting the bell housing before getting it machined to a perfect face once again. Notice the jig I built to hold the bell housing straight. If I start doing a lot of these, then I will be using a band saw for the initial cut.

Attachment 56677 Final step, installing the trans onto the motor.
It all really worked out very well and I'm so happy to be rid of that stupid huge dual mass flywheel!

or you can just run a nismo lightweight flywheel for the 6mt lol

You people just don't get it. Yes, the NISMO flywheel is the lightest flywheel you can get for this transmission, but it still weighs in at almost 14lbs and cost by itself almost a 1000 bucks. You can get a fidanza 9.5lbs flywheel and clutch assembly for under 500 bucks all day long on eBay which puts you under or right at 20lbs total. You'll never be able to beat that in the standard transmission form. My total clutch assembly weighs just 17lbs which if I do the math correctly is a mere 3lbs heavier than your NISMO flywheel. Beat that, oh you can't.

Ive been quite happy driving around with the OEM flywheel/clutch combo. A little weight and slip to keep the trans alive forever.
Let these guys keep telling themselves the six speed is weak; it brings prices down and we can stock up on them while they last :rofl:

i understand what your saying its just alot of work

and i can beat that i got my full 100% complete 6 speed swap with nismo flywheel for 400$ if you think about it thats 100$ less then u paid for your clutch setup:hide:

dont gotta get so hostile

we all love 6mt here

Not really all that much work. Now that I've done, I could do it in just a couple of hours less the time on the mill which is only about a half hour if you cut it correctly. Turns out, they've been doing this over in Aussie land for awhile now. Guess I'm not as cool as I thought.

Sometimes you want the rotating mass to help with drivability, especially in a daily driver car. I for one like not having to rev and slip the piss out of the clutch to get moving because there is no mass help move the car.

Lighter is not always better, unless you're using this is a completely racing only application.

My twin disk setup from Exedy on the 5MT is 35lbs total weight. The clutch setup I had prior was 34lbs. I'm sure clutch/flywheel weight combos play a role in the destruction of tranmissions, but if a transmission is rated for X torque, no matter how light the rotating assembly gets infront of it, you're not going to make it any "stronger".

Sweet project though. I always wanted the 6MT, but it was always more work than I wanted to do to have a true 6spd and working speedo.

I would like to add some info to this thread.

NISMO sells a speedo gear mounting kit to move the VSS from the differential to the transmission tail section. It places the VSS in the same spot as it would be in a S13 or S14. The kit comes with everything needed except the speed ring gear.
NISMO Silvia Reinforced Cross 6-Speed Transmission - Speedometer Gear Mounting Kit

No more s15 diffs and signal converters!

Enjoy.

It is something like this...Attachment 57891

My Questions are:
I already have the housing extension on the 6MT, so now where can I get a speedo drive gear from? From KA 5MT? Or SR 5MT? Looks like its not included in the Nismo kit.

The ball bearing and snap ring is it the same parts from the KA 5MT/SR 5 MT?

Would the s14 speed sensor works accurately with the s15 cluster speedometer?

You can use the nylon gear out of what tranny your using the vss out of, but you'll have to get a big unibit to drill it out to fit over the larger output shaft of the s15 tranny. I did this and it worked great. Oh you'll have to find a small ballbearing to lock the gear on too. The s13 ball bearing is too big.

Awesome thanks! Should I just buy the snap ring anywhere as long as i have the shaft diameter for it and i think i might need two right?

Yep, two snap rings, although I only used the front because the fit was so tight and the gear was too wide to get the back one in. So, if you want to use both, you'll have to narrow the nylon gear a bit, but as tight as it was after boring it out, there's no way it was going anywhere. I had to use a crescent wrench and hammer to tap it into place. Hope this helps. Cheers.

and the S-chassis auto yoke...

haven't measured the case lengths 6MT vs AT though

Yes, you have to knock off the oil slinger on the auto yoke (two little welds on either side, a cutoff wheel, and a small hammer takes care of it), but other that that the driveline fit perfect. Not sure about the length of the auto trans, but I know the six speed is shorter than the ka 5 speed. I'm not positive about the numbers but I think it's around 30"s 6spd, 33"s 5spd in length.

S15 SR with 6MT and diff. bolts on to s14, but how about the S15 stock drive shaft?

Don't know anything about the stock s15 drive line, didn't get one with my swap motor, but I would assume it is the exact same as the s13 auto drive line length and all save the oil slinger.

anyone able to help with some part #'s? (6speed) I think I have them but unverified...

shifter control housing 32515-89F00
throw out bearing 30502-69F10
throw out bearing carrier


sources;

328 - transmission shift control (unit) for Silvia S15 Nissan Silvia - Genuine parts

REPAIR PARTS | Products | EXEDY RACING CLUTCH

Nissan Release Bearing and Sleeve Set'



http://www.tomeipowered-usa.com/usa/...rp_2011oct.xls

does the transmission plate (between block/bell housing) remain the same 5 vs 6 speed?

will I require S15 part or will my S13 part work the same....

I've searched, with no luck leading me to believe its unecessary...