is a 8.25 worth doing anything with?
 

Ok, so now that I've basically fixed my XJ, and it has proven to be mostly reliable and stuff, I want to plan some actual modifications, since I don't think I'll have to keep dumping money into getting it running! trying to make some decisions on what to do.

My compiled list so far:
Bumpers - Will try my hand at fabbing something up for this. we'll see.
Roll cage - Picked out, but being saved up for
Seats - Picked out, being saved up for
wheels - on the way
Traction - Not sure what to do with this.

I of course have a D30 front axle, and last year I swapped out a D35 for a C. 8.25. I know the 8.25 is still a c-clip axle, correct? so should I bother locking it, maybe put in an LSD? or should I not do anything with it, since its not strong enough? I know the D35 wasn't worth doing anything with, but I'm not as familiar with the C. 8.25 but options seem limited compared to other axles. I do not plan on going past 33" tires until my kids are into their teens, and sticking with a 31" for a while still, so I do not plan on doing an axle upgrade before then.

as a side note, I do not know if I have 27 or 29 splines. other than spline count is there any difference between the two? is there a quick way to check without pulling the cover and counting?

Yes the c8.25 is c-clip,
Yes the 8.25 is worth locking, a LSD would do great in the c8.25.
31" you wont have to do a gear change, Well not until you do 33". Then a gear change will be needed if you don't want the jeep to be a fat pig on takeoff and highway driving

Ive read the 8.25 29 spline is close to being as strong as a D44, How close IDK.

Now I think 97+ all have the 29 spline c8.25. But if you have ABS brakes I think it will be 27 spline. Im not sure,, so do some research on that.

hope I was of help.

I have an 89 cherokee, and this axle was a used axle I got from a shop that used to break jeeps and sells the parts, it was cheaper than replacing the bearings in my D35 that were shot (pinion bearing was so bad I could wobble it around with my hand). they couldn't tell me the year of jeep it came off of, and I have no idea if it had ABS or not.

I'll probably stick with 31" tires for a long while.

Only way to find out the splines is to open it up. I'm on 33s and put in an aussie locker into my 8.25 29 spline last year. No complaints and the axle has no issues moving that weight around. No worries with a 8.25 locked below 35s, i'm sure you can snap one if you really tried on 33s or 35s. I'm running 3.55s with 33x10.50s and have no complaints but i'm along the beach where it's flat and offroad it just crawls no problem. If you have 27 splines you can swap over the shaft and carriers over to 29 but keep the housing, just have to set the gearing backlash again.

Hmmm,, damn. Then I guess the only way is to count splines.


You should check out this place, its great for the Jeep you have.
http://cruiser54.com/

Oh, I'm very familiar with cruiser's tips. I've had my XJ now almost 3 years.

Cool, good deal.

If you want a selectable locker, OX Locker makes one for the 27 spline.

Here's the link.

I haven't used it, but it's on my wish list for my XJ.

Do yourself a favor and don't invest any money in the 27 spline axles as they are quite a bit weaker than a stock set of used 29 spline shafts. Used axles are cheap and if you plan on a locker buy one for a 29 spline and do the swap.

The Chy 8.25 29 spline is a very strong differential equal to a D44 but not as many aftermarket parts for them. I run that setup with 4.56 gears and full case lockers running 33 & 35" tires so far no breakage in 4 yrs mostly off road use.

If you stick with a 31" tire you can get buy with the stock 3.55 gears any larger and it really requires a gear change for many reasons power, mpg's, trans overheating and hunting for gears to name a few.

Yeah, if I do anything, I'll plan for and buy for 29 spline axle shafts, if It is so that I have 27 splines. I'll buy new/used shafts. I don't think I'll lock it. I think I'll keep it to a limited slip, and lock the front.

Sorry for the thread hijack, but what makes the 27 spline significantly weaker than a 29 spline? From my (admittedly limited) research on this forum, the 27 spline still seems like a decent axle.

Not trying to argue, just trying to learn... :detective:

I might be wrong, but I think splines are the same size, so more splines = Thicker axle shaft = stronger? that's just a guess on my part.

I know a guy that had a 27 spline 8.25 locked on 33s. He never had a issue. Another guy I know has the 29 version locked on 33s & beats it like a rental. Both utilize stock shafts. They are pretty huge.
Note: you can't just get used 29 spline shafts & stick them in a 27 spline rear axle. The carrier itself is also 27 spline. I had a 27 spline rear & tried to stick the 29 spline shaft into it. Fail!

Oh I know that. i would upgrade IF I upgraded to a LSD, I would get a 29 spline one, and then upgrade the axles as needed (well I would check first before buying anything).

Its the size of the shaft itself in one area prone to breakage, along with an extra 2 splines for added strength. The cost is so cheap that most do it just for the added safety factor and not breaking an axle.