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what year of AW4 went to 23 spline


NAXJA Forum User
I have several 21 spline older aw4's but need a 23 spline for a project...what year did they change, and will an older wiring harness work with the newer transmissions..did any of teh older models have 23 spline.
From what I've heard the wiring harness has a different "plug(?)" count, but you can just snip and solder. Also check the lenth of the shaft.

I'm also considering upping to a 23 spline when the ol' motor gets stroked. But the real question is will a mildly stroked motor snap a 21 spline shaft? I don't *think* so...Has anyone seen this happen? I'd rather not deal with it unless it's necessary. I'd like the extra power for mountain passes, but I won't be competing in side shows with the rice burners.

Besides, all the torque reduction is done after the tranny output shaft, as you get further down the drive train, as in the t-case, (or in xjnations case, the K-V AND the t-case) that's where the torque happens.
Im actually gonna probably put a 4.0 and aw4 in a scout with a dana 300...the motor mounts for a 258 will bolt right up..just gotta do some cross member fab work
90 and older are 21 spline. AW4's went 23 spline in 91 with the 4.0 HO.

As far as problems with the 21 spline output, I see no problem with it. I built Wombat's (on here) XJ last winter with a very modded 4.?, 4:1, D44's, 36's, and repeated 6000 RPM launches with no problems at all.

Well, aside from broken Warn front shafts :)
I 'think' the seperate TCU was similar from the AW4 intro in 87 through whenever OBDII came out (95?) With OBDII, the engine & tranny computers became integrated.

I may have it wrong though so get a 2nd opinion ;)