27 spline or 29 spline?

I have a 1996 XJ with the Chrysler 8.25 axle. I have heard that some from this year have a 27 spline axle, while others have a 29 spline. Is this true? If it is, how do I know which I have?

I saw a post a few weeks back that regarded checking the ID band on the axle and matching it with a series of number codes. That is if still there after all these years. Only other way is to pull of the hardware and check the shaft itself

If its a '96, it most likely has the 27 spline. '97 and newer have the 29 spline, but depending on when it was made in '96 you may have a 29 spline.

why are you changing to a 242???

You are right in that changeover year, possible you could get a jeep build sheet from the dealer which would have the 8.25 part number and get a breakdown from there. I'd stop at a good dealer and go ask, they might be able to tell from the vin number.
Short of removing and axle and counting I don't know any quick way, though you *might* be able to open the cover and see either the end of the axle or where the splines end on the axle.
Anybody know off hand if the 8.25 axles have their part number stamped on the stud flange, if so you might just be able to remove tire and then the drum.

As for changing to a 242, thats something I have thought about if my 231 goes bad, then I can post questions about where to get that extra plug from for the dash light indicator...

Ok, I guess I'll look for some numbers on the axle next time I'm working on it. Thanks guys!