x case ? before i chuck it in the trash.

[ilco187]

I have a 90 gsx 22 spline xcase and its no use at all tried selling it on here with no luck and even tried just giving it away to locals but still nobody wants it. so to make it useful can i swap the 22 spline input out and put in a 23 spline input in or is the 91 and 90 22 vs 23 have more differences inside than just a spline count.

 

[And_44]

The gear ratios are the same only difference internally is for 2g x-cases. And the differnce for the one you got is spline count.

 

[twicks69]

You can use the 90 transfer case on any 1990-96 vehicle with just an output shaft swap, OTHERWISE, if you want to spend $300 on a replacement receiver sleeve (the portion of the transfer case that the output shaft slides into) you can disasseemble your transfer case side cover, pull the "ring gear" portion of it out that incorporates the sleeve, then seperate it using a press and gear splitters (OTC1123, press, press tools, etc.)

The 1990 22-spline sleeve is MD726967.
The 1991-1999 23-spline sleeve is MD741189.
The 1990 22-spline transmission output shaft is MD735643.
The 1991-1999 23-spline transmission output shaft is MD741190.

The transfer case receivers themselves are interchangable, so you can make a 1990 transfer case 23-spline if you want, as well as making a 1991-1999 transfer case into a 22-spline if you really wanted to.

The transfer case ring and pinion gear ratios are only different between 1990-1996 vs. 1997-1999 for the actual gear that presses onto the receiver sleeve. As well, the front differential ring gear inside the transmission is only different for tooth count from 1990-1996 vs. 1997-1999.

The transfer case ring and pinion part numbers are as follows:
1990-1996: MD756514
1997-1999: MD756623

The front differential transmission ring gear part numbers are as follows:
1989-1991.05.2 - MD726425 = 58-teeth
1991.05.3-1996.06.3 - MD748872 = 58-teeth
1996.07.1-1999 - MD770499 = 57-teeth

The output pinion shaft (matching pinion gear for above) part numbers are as follows:

1989-1991.05.2 - MD727761
1991.05.3-1999 - MD742530

There are different gear tooth profiles/pitches on the front diff ring gear and pinion gears for the two 58-tooth units, so you would want to use a matching set. In the past, there were two other variations used that were superceded by these part numbers.

 

[ilco187]

Yeah im just gonna swap the receivers. i took the 22 spline apart is so super clean and has no tail shaft play at all. the one in the car however i tried to drain it and it was not even a fluid anymore it was a black/greyish paste and the tail shaft has alot of play.

 

[twicks69]

Sorry, I should have clarified in the first post; I have updated it to clarify what we are talking about.

There is no difference in the receiver sleeve from 1991-1999; it is only the ring and pinion gear inside the transfer case and the ring gear on the front differential that are different.

I have attached two images to describe what I am specifically talking about.

For the transfer case image, we are talking about part number item #30452, and the transmission image (2nd image), we are talking about part number item #22626.

This thread was not meant to be a "can I put this 90 transfer case on my 97-99 DSM?", it was meant to cover the question of "can I use this 22-spline 1990 transfer case on my 1G 23-spline transmission, and how do I do it?"

If you wanted to use the 1990 transfer case (case assembly) with a 1997-1999 ring and pinion (transfer case gears) and a 22-spline input sleeve with a 97-99 front diff ring gear, you can then simply disassemble it, swap receivers, re-shim the ring/pinion gearset inside the transfer case after pulling all the bearing races and either replacing the bearings/races or swapping them over and then doing a reshim/gearlash job on it. Again, this was not the topic of conversation specifically for this thread.

 

[ilco187]

thanks for the help.