Jeep Cherokee Forum - Chrysler 8.25 rear diff issue

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Chrysler 8.25 rear diff issue

I have several questions and I’m not very adept when it comes to diffiernials so please have patience and understanding. I’m in the process of updating my 97 XJ. Rebuilt engine, rust remediation, lots of wiring, cleaning, you get the picture.

So..... I pulled my diff cover and the oil looked murky. My first thought was, well that’s not good, got new seals and am in the process of doing a drum to disk brake conversion so no big deal. The problem is none for the seals looked bad. I pulled the axel out to clean and look it over better and when I pulled the brake line/vent connector i didn’t find any O rings or sealant on it. Could this be where water was getting into the axel?
Secondly, i found I have a Detroit truetrac locker, Bonus!!! However, I pulled the carrier (first time so I hope I’m not jacking anything up..... when I did I noticed one of the bearings and it’s race looked pretty eaten up most likely from the water that had gotten in.
Are these bearing hard to press in and out? Am I over my head and should I take it to a pro?
I attached a few pictures. Please feel free to be honest. Thx. Tony
https://cimg0.ibsrv.net/gimg/www.che...0a5c3340b.jpeg
https://cimg1.ibsrv.net/gimg/www.che...ef2af87f9.jpeg
https://cimg2.ibsrv.net/gimg/www.che...772fc1c3a.jpeg
https://cimg3.ibsrv.net/gimg/www.che...2c7594fae.jpeg

I would recommend replacing them, you can cut the old bearings off with an angle grinder if your careful. If you don't have a press you can put the carrier in the freezer and the new bearings in the oven at 350* for 30 minutes and they will generally go on easily. When you put the carrier back be sure to set your backlash with a dial indicator.

I have access to a press. That’s not a problem, I have no experience setting backlash or any kinda clearances with diff gears. I rebuilt my 4.0 but for some reason diffs kinda freak me out.
How about my first question that relates to how the water got in there in the first place. Any thoughts ?

The cover gasket, axle seals, pinion seal and breather are the only places water can get in. Make sure none of your seals are leaking and extend the breather tube to keep water out.

Quote:

Originally Posted by lvtraveler (Post 3535110)

The problem is none for the seals looked bad.

While it's possible that's just years of condensation contaminating the gear oil it's a lot more likely the vehicle was swamped and the seals are shot.

Quote:

Originally Posted by lvtraveler (Post 3535110)

Am I over my head and should I take it to a pro?

You might as well replace the pinion bearings sooner rather than later and the gear set has to be set up from scratch. If you expect this to last 100,000 miles it's a good idea to take it to someone with a lot of prior experience, it's not a good beginner project. It is a perfect opportunity to re-gear it tho.

If the bearings have rust damage, the ring and pinion are probably damaged too.
It might be better to find a good, used 8.25. Setting up 8.25 isn't a beginner project.