I was wondering how many splines on a np231 that is in a 1989 yj 6cy with and auto. I just bought the yj and didn't realize the t-case was cracked, front drive shaft pogo'd the t-case. I have some out of a 4 cyl 5 speed (21 spline), can the input shafts be interchanged between the t-cases??


Craig

Originally posted by CrazyCraig
I was wondering how many splines on a np231 that is in a 1989 yj 6cy with and auto. I just bought the yj and didn't realize the t-case was cracked, front drive shaft pogo'd the t-case. I have some out of a 4 cyl 5 speed (21 spline), can the input shafts be interchanged between the t-cases??


Craig

Should be 23 spline with the auto, according to an AA table I have.

89 was a funky year with the AW4 231 combo. Some of them had 21 spline. Gotta pull it and check.

Yes, the input shafts can be swapped

89s with the 6 and auto had the TF999 not the Asin tranny. And its 23 spline.
Rick

What year is the 4 cyl t-case. If both cases are YJ cases all the parts are intercangable. The case behind the auto will be a "long" 23 spline input. The 4 cyl, 5 spd will have a "short" 21 spline input. T-cases with AX-15's in front of them had "short" 23 spline shafts. You can not swap TJ t-case input parts because they changed the input bearing style. In short it the cases are both from a YJ or XJ you can swap parts. I would buy a new chain while you have it apart, but that is just my $.02.