The Top DSM Community on the Web

For 1990-1999 Mitsubishi Eclipse, Eagle Talon, Plymouth Laser, and Galant VR-4 Owners. Log in to remove most ads.

Please Support JNZ Tuning
Please Support Fuel Injector Clinic

2G Transfer Case / Spline Problem - Shed some light??

This site may earn a commission from merchant
affiliate links, including eBay, Amazon, and others.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

techboy

5+ Year Contributor
534
420
Feb 3, 2018
Lehigh Valley, Pennsylvania
So I ran into a major snag with my AWD swap last night. I spent an hour or so trying to install the transfer case and it just wouldn't slide on. I gave up and went to bed. I got to thinking today that maybe there was an issue with the splines. I had checked and double checked the output gear ratio, but never the input shaft splines. So, it turns out my transfer case is a 22 spline while the replacement trans I picked up is a 23 spline. Here's where I get a little confused and could use some insight. I had to replace the original trans that came with my donor car for the AWD swap b/c it was damaged. The number on that trans was KW5M332NPZT. I made sure when I purchased my replacement it bore the same number so I wouldn't run into T-case issues. I still have the old trans, and when I go back and count the splines on the input shaft it counts 22 as well (same as T-case).

As far as T-cases go, it has been my understanding through research that 89-90 T-cases had a 22 spline count and where in an all aluminum housing. The 91-99 all had a 23 spline with the 97-99's having the different gear ratio on the output. Unless I am crazy, my T-case is not all aluminum .... here it is before I painted it.
You must be logged in to view this image or video.


You must be logged in to view this image or video.


Here's a few things I know. My donor car was a 97 Talon. Originally it was an auto, someone swapped it to a manual, so the trans and T-case where not original. Other than the Transmission code I provided, I don't know what year car they came from, other than obviously not being a 97-99 b/c the T-case has a 1.090 drive ratio. The transmission I bought (with the same code) the owner said came from a 95.

So, here are my questions:
Can anyone shed light on why I have 2 transmissions with the same code but two different spline output shafts?
How is it that I have a T-case w/ 22 splines that's not all aluminum? (someone swapped parts maybe?)
How hard is it to swap the output shafts on the transmissions since I do have the correct 22 spline sitting on my garage floor?
Is it possible/easier to track down a 23 spline female shaft and swap it into my current T-case? Is that part even available separately?
Is it easier to just get a whole other 23 spline 90-96 T-case?

I know it's my fault for not actually counting the splines before getting this far, but I was so focused on making sure the final drive gear ratio was correct and knew that my T-case wasn't all aluminum, I didn't even think to look at the splines. Needless to say I'm a bit frustrated as I thought I was just a few days/week away from finishing this project. Looking for input / thoughts.

Thanks.
 
Last edited:
Can anyone shed light on why I have 2 transmissions with the same code but two different spline input shafts?
Most likely somebody swapped the output shaft before.

How is it that I have a T-case w/ 22 splines that's not all aluminum? (someone swapped parts maybe?)
How hard is it to swap the input shafts on the transmissions since I do have the correct 22 spline sitting on my garage floor?
Is it possible/easier to track down a 23 spline female input shaft and swap it into my current T-case? Is that part even available separately?
Is it easier to just get a whole other 23 spline 90-96 T-case?
Somebody swapped the parts or I have heard that a few 22 spline t-case came with cast front case housing instead of aluminum, I have never seen it though.

You don't need to swap the transmission input shaft, what you need to swap is the output shaft and that would be an easy process. Read the post #5 in the link below.
https://www.dsmtuners.com/threads/98-gsx-output-shaft-removal-install.362344/

I'm not sure which spline count you want to go with but just swap the output shaft on transmission to match with the t-case that you want to use.
 
Iron front case transfer cases were found in 90 models that received the transfer case recall and also received a new transfer case as a result of the recall. I receive one when I had my recall done. Her the previous post swapping the output shaft of the transmission is easy. I would make damn sure you are correct about the ratios of a transmission and T case. Do not assume that because this came from a running car it is correct. Is completely possible that the reason it is a donor car is because somebody did the swap incorrectly. Verify for yourself
 
Thanks for both the replies. I guess maybe this was a recall T- case. I looked at the link provided. Swapping the output shaft doesnt look that difficult, so I may give that route a try. However, it seems to me 22 spline cases are much less common, so I'm wondering if I would be better just tracking down a 23 spline case so that when I break stuff in the future I'm not trying to find hard to find parts. I installed my trans already, can I swap the output shaft with it in the car, or do need to take it back out?

I will definitely re-check the drive ratios. I'm 100% sure the T- case has a 1.090 ratio and the trans I have now is from a 95 Eclipse, so they should match. I will verify again though.
 
I, too, have a 22 spline Iron head case and it was in a recall 1990 GSX (along with a few aluminum head units). You can swap to a 23 spline relatively easy and, like you said, use the more widely available 23 splines, with the iron head. On a side note, only the iron head units can use the Frontline Fab brace, the aluminum head models (which REALLY need it) will not work with Andrew's billet brace.
 
I, too, have a 22 spline Iron head case and it was in a recall 1990 GSX (along with a few aluminum head units). You can swap to a 23 spline relatively easy and, like you said, use the more widely available 23 splines, with the iron head. On a side note, only the iron head units can use the Frontline Fab brace, the aluminum head models (which REALLY need it) will not work with Andrew's billet brace.

So your saying it is possible to swap a 23 spline female into my current T-case without too much trouble. Since my trans is already installed, that's my preferred solution. Id hate to work backwards and pull my trans back out to swap output shafts.
 
So your saying it is possible to swap a 23 spline female into my current T-case without too much trouble. Since my trans is already installed, that's my preferred solution. Id hate to work backwards and pull my trans back out to swap output shafts.

You could pull the oil pan and slide the shaft out after removing the viscous coupler and check ball. Less heavy lifting, more tedious work.
 
So your saying it is possible to swap a 23 spline female into my current T-case without too much trouble. Since my trans is already installed, that's my preferred solution. Id hate to work backwards and pull my trans back out to swap output shafts.
You don't have to remove the trans to swap the output shaft. You also do not have to remove the oil pan. Swapping the output shaft is the quickest and easiest solution. There is already some information posted above that told you how to do it. Since it is easy to swap shafts it isn't a big deal to run a 22 spline case. If you need to use a 23 spline case Slater just swap the shafts again. There is also no need for bearing shimming or any precision work regarding changing the output shaft. It is a very straightforward easy change.
 
You don't have to remove the trans to swap the output shaft. You also do not have to remove the oil pan. Swapping the output shaft is the quickest and easiest solution. There is already some information posted above that told you how to do it. Since it is easy to swap shafts it isn't a big deal to run a 22 spline case. If you need to use a 23 spline case Slater just swap the shafts again. There is also no need for bearing shimming or any precision work regarding changing the output shaft. It is a very straightforward easy change.

Yeah, I looked at that post, it certainly didn't look like anything that would be too hard to do. Plus, I get to practice the removal of the 22 spline output shaft from the trans that is sitting on my garage floor before I crack my good one open. The other nice part is there is no fluid in it.

The other idea I had was to contact Jacks or TMZ for a stage 1 or 2 rebuild and see if they could switch it to 23 spline during the process. I know swapping shafts would cost me zero dollars, and a rebuild is a bit more, but it might be worth since I really don't know much about the history of my T-case. I'm gonna email each and see what they come back with.
 
UPDATE: Thanks to all who chimed in on this thread. I was able to swap the shafts today no problem. So I'm now running 22 splines. I took a bunch of pictures, so when I have some time Ill put together a How-To.
 
Support Vendors who Support the DSM Community
Boosted Fabrication ECM Tuning ExtremePSI Fuel Injector Clinic Innovation Products Jacks Transmissions JNZ Tuning Kiggly Racing Morrison Fabrications MyMitsubishiStore.com RixRacing RockAuto RTM Racing STM Tuned

Latest posts

Build Thread Updates

Vendor Updates

Latest Classifieds

Back
Top