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8.25/27 spline options

W

Whiskey

NAXJA Forum User
Location
Mission, BC
I've got a '94 XJ, 4.0, auto, 27 spline 8.25 diff.


What are my options for upgrading the diff?


I'm hoping to run 33 or 35 tires with 4.56-4.88 gears and lockers. What is the cheapest/best way to upgrade?
I see the options as:
-trying to find a Dana 44 from an older XJ and swap it in
-finding a Ford 8.8 and converting it for my XJ
-upgrading the shafts/etc from an aftermarket axle company (Yukon)


Can I put 29 spline shafts in my diff if I also change out the gearing? Are there more parts in the diff that I'd need to switch out?


I guess I'm looking for the most cost effective way to enable my XJ to handle the additional strain of larger tires and a locker.


Thanks.
 
Had to look for it, and I don't think so. After all, there's no way to tell without counting whether it's the 27- or 29-spline, although a little voice in my head is saying something about the left and right sides being equal-length on the 29s. Don't hold me to that one though, it's been a year-plus since I've dealt with XJs and I'm coming back up to speed.

Anyway, mid-96 was the changeover. In typical Jeep fashion I wouldn't be surprised if the change to 29s happened one week, then they found (and used) a binful of 27s again...then 29s and a few leftover 27s...etc.

Jim www.yuccaman.com/jeep
 
27-spline and 29-spline shafts are the same lengths. And you'd also have to swap out the carrier to upgrade to 29-spline shafts. Unless you put in a full replacement locker (Detroit, ARB, OX, Truetrac, et al).
 
Not doubting you, but are you sure about that carrier comment? Granted, my brain's a little dusty right now on this, but I was pretty certain it was just side gears that were needed. If there's a new carrier involved, that's going to require just a little more work. Might be a good time to regear as well.

Jim
 
Yes,you must change the carrier,side gears,and axle shafts.
 
seals, carrier, shafts, etc.
 
why not justswap in a 29 spline rear end, thats what I did. Added the Ausie locker before, much easier
 
Picked up my 29 spline for $150 from Tyler.
 
nick86 said:
why not justswap in a 29 spline rear end, thats what I did. Added the Ausie locker before, much easier
Click to expand...
(Mental note noted about the 29-spline upgrade).

Okay, I'm officially changing my answer of 'cheapest' to this.

Jim www.yuccaman.com/jeep
 
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