98 xj - 8.25 rear axle seal

98 XJ - 8.25 rear axle w/ 4.10 gears and posi.

1. Right drum is coated in a super heavy oil or grease. Seems to be coming from the axle. The stuff is super thick, but may be just a lot of mud/water mixed with gear oil?
I don't know what seals what in an axle/diff. Gear oil makes it's way into the axle or should that be sealed off? If something's leaking out my axle seal, is that going to be gear oil?

2. If this is just gear oil from the diff and my axle seal is toast, does anyone know if this axle should have the seal pressed onto the axle or into the axle housing? I don't have the tools to cut a seal/bearing off the axle but I think I have a slide hammer to pull an axle housing seal out just fine.

Also, once I've got this all apart, what kind of gear oil goes in there? Read a tonne of posts but everyone just lists a brand and when weights are listed, they're inconsistent.

Open your 8.25 fill plug and check the fluid level. The fluid should be level with the bottom part of the fill port. If not, you are low on fluid. Diff flluid weight will be different based on your usage, ie towing, racing, etc.

Most diff leaks will come from either pinion seal, diff cover, or fill plug. You can use simple green (or go to a car wash with a proper grease drain) and clean off all residue to find the source of the leak.

Just a few words to get you started. Good luck.

Unless you are having other issues with the axle, it's ok. Seal leakage is pretty common on trail rigs and are not that difficult to replace.

1) Place your rig on jack stands
2) Remove the rear tire
3) Remove the rear Diff cover/drain the pumpkin
4) Remove the pinion shaft from the diff
5) Push in the rear axle to remove the "C" clip
6) Remove the axle shaft from the tube
7) Remove the old seal
8) Clean all your brake component of 90wt oil
9) Replace the seal with new one.
Lightly tap it in with a hammer and a block of wood. A piece of 2x4 works just great. This prevents damaging the new seal.
10) Grease the rubber sealing surface of the new seal to prevent damage to the rubber during re-assembling.

Reverse the disassemble process and you are done.

A word of caution however. If one seal is worn, the other one is not that far off from failure too. If they have that same amount of time and milage as the one you just replaced, you might as well replace both seals. It cheap insurance and peace of mind. Also, if your brakes are coated with 90 wt. Chances are it is soakes into the linings. There is no amount of brake clean that will remove the oil once it has soaked in. You will have to replace you brake shoes too. Otherwise your rig will not stop all that well and can also cause a brake fire if they get hot enough. :flame:

Good luck

@Norsk62, Thx. That's sorta what I figured, just wasn't sure if the diff oil COULD leak out the axle seal as I wasn't sure if there was another seal to keep the diff oil out of the axle, and I've had guys tell me to put grease in the axle housing as well.....

So how to remove the old seal? Slide hammer the only way?
Also, mostly highway/city driving and the occasional weekend in the mud or hill climb. 90wt gear oil? synth?

Also planning on swapping a set of liberty rear discs in so won't worry about replacing the shoes on the old drums.

Any recommendations for the disc conv? Everything I've found says to just grab a set off any year Liberty and bolt'm on. This sound right?

"Also, mostly highway/city driving and the occasional weekend in the mud or hill climb. 90wt gear oil? synth?"

In your OP you said you had a posi unit. If that's correct, a reminder to also add the correct amount of friction modifier. To leave it out will cause some clutch issues, mostly chattering and growling in corners.

HTH
Bob

XXXX! Thanks Azhobo! Totally forgot about that.
How do I figure out how much/what type?

XXXX was profanity... I'm not THAT grateful.

"XXXX was profanity. I'm not that grateful."

Thanks, I appreciate that............:laugh3:

Not sure if y'all have AutoZone in the Great White North, but if so, they carry a small plastic jar of friction modifier, maybe around 8-10 ounces. We used one full bottle for my sons Chry 8.25 posi rear. Results were immediate and excellent. The maker recommends doing some figure 8 turns after using to mix up the oil/modifier. We could tell it was working by the 4th set of turns.
As an afterthought................ you asked about type of gear oil. Here in the AZ desert, I kinda prefer the synthetics due to our higher ambient temps, but I suspect you'd be good to go using straight 90W. Kinda doubt you see many 100 plus degree days, do you? Maybe if you do considerable amounts of towing the cost would be worthwhile, not sure.
Bob

I use Amsoil SevereGear 75w-110front and rear. This does not require the modifier, but you can use it fine. Some full syn gear oils do not require the add'l modifier.
Pick yourself up a lubelocker gasket. Worth every penny. No more scraping/silicone again.

1.Axle seal is in the axle tube, wheel side, should be the first thing you see after removing the axle shaft.
2.I don't know. I can't think of any reason for special indexing of the axle shaft. Someone correct me if I'm wrong. I don't believe it's possible to put back together incorrectly.
3.Special tools - Slide hammer may be necessary to remove the bearing if you're pulling it as well, but the seal should just pop out AFAIK.
4.I've put about 20,000KM on my rig since I bought it. The axle seal's been leaking the entire time. I haven't died yet and the bearing still sounds/feels okay. I think it's mostly a matter of "if you run outta gear oil, you'll kill your gears and wheel bearings". If it's leaking as bad as mine, you'll also coat your brakes in gear oil and you'll have to replace the shoes/pads.

All this said, I think I'm going to take this as an opportunity to re-shim my gears, replace all my wheel bearings, and swap out those awful drums with a set of disc brakes off an 05 Liberty. Should bolt right up and you can get a set from a wrecker for $50. Seems sorta silly not to do the swap at the same time as the gear oil costs $65 here and the axle shafts have gotta come out to do the brake swap.

Sorry for not replaying earlier. The axle seals are on the wheel side of axel tube. A standard seal remover will work if the outer seal is not frozen to the tube. If so, then it's a slide hammer. I had to use a chisle and it was hammer time.