27 or 31 splined 8.8?

BigClay

BigClay

Knower of useless ZJ things
Joined
Sep 24, 2008
Location
Winston-Salem
So I have a 8.8 under the rear of my TJ, but the previous owner didn't know what the donor vehicle was. There are 27 and 31 spline 8.8s. Besides pulling the axle shafts and counting the splines, is there anyway for me to be reasonable sure that my 8.8 is 31 spline?

The axle does have disc brakes, but those could have been swapped on, I do not know.
 
Is it an open diff?
 
Open diff, at least I think, I haven't pulled the cover yet to verify.
 
Unfortunately the tag is gone
 
Lee said:
If it is disk then it is most likely a 31 spline from an Explorer. The drum brake axles were mostly 28
Click to expand...

I agree, but discs can be installed on a drum axle. It's unlikely that somebody would go to that trouble nd not upgrade the shafts, but they went to the trouble and expense of installing an 8.8 and didn't put a locker in it....
 
Lots of variables with ford 8.8's. At least you get to change the gear oil while your fishing for a c-clip, and you will probably get interrupted at least twice while trying to count splines.

At one point I had a GM 10-bolt in the rear of my CJ (gasp), I had it apart so many times that I started taking it loose from the springs and pointing the pinion down so I didnt have to buy new oil....
 
Thanks guys, I know that it is more likely than not that it is 31 splines, but with my luck I could assume that and be sadly mistaken when I go to install a locker.
 
I would probably still buy a 31 spline locker, and if it doesnt fit you have a good reason to upgrade the shafts.
 
Back
Top