sye problem well kinda

[nismo5]

so my problem is i have an 89 xj with a aw4 and np 231 21 spline i think? and a while back i bought a 231 with a sye already installed without doing much research turns out its a nv 231 23 spline from a 97 now that i looked at it.

ive read a bunch of threads but im just not clear on the whole thing i know the spline count changed right around there but some people said that some 89's and 90's randomly had either 21 or 23 just a luck of the draw kinda thing i wont know till i get my jeep back(long story) and tear it apart.

so im just gonna assume i have a 21 spline and im just wondering what my options are ive read threads about changing the input shaft on the t-case to a 21 spline but alot of threads about how they changed some internal stuff and some it wont work on ive never torn apart a t-case so im not even sure what parts/gears they were talkin about but if that wont work would i be able to just uninstall the sye and install it in my 21 spline thats in there right now??

or even any options i have missed would help it all got a little confusing :smiley-scared002:so i figured i would ask the experts :)sorry for the long post

[W.O.R.P.Offroad]

if you have a auto its a 21 spline. i cant mem the exact year they changed but it was after 90. it is pretty easy to change the inputs shafts out.

i have the factory over haul manual for the 231. the exploded view in it makes it look scarier than it really is.

i will send you 2 different manuals. one is derived from the jeep fsm the other is just on the case.

if you give me your email i can send it to you. its to big to post on here.
my email is [email protected] in the email tell me its about the tc manuals

[nismo5]

my main concern is that from what i read there are all different styles of input shafts cause they changed companies from np to nv and that i have to find the right kind even if the swap is easy

[Mudderoy]

my main concern is that from what i read there are all different styles of input shafts cause they changed companies from np to nv and that i have to find the right kind even if the swap is easy

New Process and New Venture are the same company.

[rguignard]

New Process and New Venture are the same company.

2x there are only 2 spline counts 21 and 23 so it just change it out if its wrong :thumbsup:

[4.3LXJ]

Tom, just take the SYE off the new case and put it on the old one. You don't have to change as many parts that way either. Advance Adapters only lists one SYE for the 231

[nismo5]

i googl'ed it and this is what i was sayin(below is a quote from a thread on pirate) they changed some stuff in the case so swappin inputs i would need a 97 and up attached to a 4 cyl 5 speed and there isnt any at chico pnp think ima have to go with 4.3 on this one and maybe even take advantage of one of your wrench days steve :thumbsup:since ive never been inside a case yet oh and my name is tim :)

(pirate thread quote )
I have seen a few break, But to answer your question. In order to change that 1999 np231 to 21 spline, You better be careful on the year of the input. In 1995 New Venture Gear changed the planetary assembly in the np231. The bearing on the input changed, as well as the pitch on the input gear. The pitch is the problem. Most older input gears won't slide into a newer planetary assembly. Since the AW4 has a possitive stickout, You will need a short 21 spline input. The 4cyl ax5 transmission used both a possitive and flush output shaft stickout. It was flush until 1996, and in 1997 the transmission went to a possitive stickout. In order to change your 1999 np231 to a short 21 spline input, You will need to make sure the 21 spline input is out of a 1997 or newer np231 that was mated to a 4cyl 5 speed transmission

[SargDeath]

When I did mine I have a 90xj which is automatic and it was 21 I believe

[W.O.R.P.Offroad]

i sent you those .pdf's earlier.

[nismo5]

thanks worp much appreciated