Jeep Grand Cherokee / Differential Seal Repair

If all it needs is a seal, yes. That model has issues with the rear yoke and housing assembly if I remember correctly. See how much you can wiggle the yoke in the housing, a seal may not be enough.

HI There. I had the same on my 1995 Grand Cherokee. Had the dealers replace the pinion seal and it fixed the leak. 12 months later had a bad nasty sound like a wheel bering going. Went to a local garage (no jeep dealer) and he said that it sounded like when they replaced the pinion seal they put the rattle gun on the nut and over tightened it and put too much per-load on the pinion bearings. It is important that the right tension is applied to the nut.
Upon stripping the diff we found that this was the case, the dealer workshop had over tightened the pinion yoke nut. This has the same effect on the bearings as it would have on a set of wheel bearings being over tightened.
So be carefull of getting the seal fitted by a guy who knows what he is doing.

Good Luck.

Clive

I thought I would try to inject some more life into this question by posting up a picture of the differential and see if that would generate some additional feedback.



To my way of thinking, it almost appears as though the seal around the rear of the differential has failed maybe at the bolt at the twelve or one o'clock position positions on the bolt pattern. I'm not sure I really know about the center seal on the back of the differential. I figure that seal is the opening that you would pour the differential oil/lubricant after the differential is assembled or repaired. While I recognize the pinion seal terminology, I'm not sure I would know a pinion seal if it snuck up and bit me on the ear. If this whole problem only requires a disassembly of that rear plate on the differential, the replacement of the gasket and then the replacement of the differential oil/lubricant, then I've got to believe that this repair is well within my mechanical capability.

Any other feedback from the collective audience as a result of posting the image of the offending leaking differential problem?

Thanks!

If it is the differential cover gasket that is the problem (that is the side you are picturing), that is simple. Replace the gasket and march on.

The pinion seal is on the other side, and requires much more care and or knowledge.

I must add, however that the leak would only be able to occur from a bolt in the upper half if the unit is very overfull. The fluid level is only about half way up....

Second thing could make an upper half bolt leak, and might not require opening the diff. Check the breather valve on top of the unit to see that it is open and free...

RH

How much fluid is leaking? is it dripping onto the floor consistently?

It Seems like a lot of trouble to go to for a minor seep.

Clean up the whole area with a high pressure washer and see what transpires.


Risks:
striping breaking the bolts whilst undoing.
Pain the ass to remove those top bolts.
Getting the faces clean and smooth enough to make a better seal.
Stripping the bolt threads when reinstalling.

Not worth the trouble in my opinion.

Rockhead knows more than me though.

Okay, that picture wasn't exactly worth a thousand words, but those darn old Chinese were sure right about the value of a picture though.

I mostly go along with rockhead on his spin on the situation. In response to dadpad, I can tell you that the leak has been mostly a consistent, albeit very slow leak. That said, I've lately noted a little slippage in the torque from the differential, so while some of those risks are legitimate, I can't see just pressure washing the stains away and hoping for the best - since at some point the differential is going to go dry, and I'm guessing that can't possibly be a good thing.

All the risks acknowledged, I think the smart play is to go the route of just replacing the differential gasket. I've replaced head gaskets and water pump gaskets, so I can't imagine this effort can me much different. I'm a little unclear on how exactly you get the differential oil/lubricant into the differential after the gasket has been replaced. And I seem to recall that the differential calls for a special gear oil or something, right?

Before you open it, check the vent....

Now, there is a pipe plug about halfway up, prob on the front, cuz I don't see it in the pic. That is the fill / is it full plug. take it out, it is probably a square head.

Before you go further, is it full now?

Fill it til it starts to run out, put the plug in, check the vent, and wait.

Get back to us then, and don't break the seal just yet...

Your owners manual will teel you about the fluid, but I'm real sure it is just 80/w90 gear lube...

RH

I didn't mean not ever doing anything. I meant clean it and watch to see where it starts to leak and how much.



its sometimes easier and cheaper to top up occasionally. Just check the fluid level every service. From what I can see there is bugger all oil leaking so it may only need topping up once a year. As rockhead says there will be a bolt in the casing for topping up. You may need a pump and tubing to get the oil in as diff filler plugs are hard to access with a full bottle. Full change of diff oil may be the go whilst you are servicing it.

The pic and link below isnt a jeep cherokee but the steps are the similar.



change the diff oil

dad's right, fill it up and observe for a bit...but check the vent...

it appears that the oil is leaking from the fill plug.that plug is rubber and can be pried off with a screwdriver.take it off and put a finger in side to see if there is oil in the diff.if not then top up until oil starts to run out.clean up the plug and where it goes then a light smear of slastic and just push it back in then your leak should be fixed.

He is correct as to the rubber plug, now that I put my glasses on.

However, that plug will not survive, get a new one before you play with it...

Got any help for a lady with a tired Grand Cheer? My differential lube is emptying out of the breather all over the engine and stuff. Someone filled it again and yup you guessed it, it all came out as soon as I got a few miles down the road. I recently went into the ditch and was wondering if that could have done some damage? Also I hear a clicking sound when I turn left or right and that wasn't there before.

I dont see much coming from the diff cover looks more like around the break lines. I think that is a diff vent tube that screws down into the axle housing, make sure that is tight. if you looke under a lot of high milege autos they look the same. If it is not running out, or a steady drip it should be fine. Also check fluid. The inner seal could be bad and that requires more that removing diff cover. Break lines do need replaced soon. Hope I helped. Green Scorpion