91cavgt

I need help diagnosing what I think it a shelled rear diff, but it could be more, I dunno.

Here's the back story;

About 3 hours ago I bought a '95 Jeep Cherokee Limited. I test drove it and it ran great, no problems at all. So we fill out all the paper work and my wife then proceeds to follow me back home to The Colony (we bought it in Waxahachie). I get about 2 miles from my house and come to a stop light and I smell the horrible smell of burnt diff fluid. So, I take it nice and easy and slowly go the other 2 miles home with hazard lights on. About 1/2 a mile from my house I go around a corner and hear some REALLY bad grinding noises and the whole Jeep is just shimmying back and forth while going straight (easy to keep in my lane but it felt like it didn't want to track in a straight line).


So, it's sitting in front of my house right now. Yesterday I sold my former daily driver and with the money I made from it I bought this Jeep. Now I'm screwed. I need some help trying to find out exactly what it wrong with this Jeep so I can determine A. if it's worth fixing and B. what is it going to cost me. I am a diesel mechanic be trade and can do most repairs in my driveway, but I don't want to replace the diff and it end up being something else, so I'd like some help from someone that knows these Jeeps just to try to diagnose the problem.

I've owned 16 cars in my life (only 3 of those were brand new) and I've never bought a vehicle that broke down like this right after I bought it. I'm mad at myself now for selling a reliable daily driver and for letting my family down.

OverlandZJ

Pull the cover, lets see whats inside. Check for fresh fingerprints..

Might be cheaper and easier to just swap in another axle.

91cavgt

That's what I was planning on doing tomorrow morning. I'm also gonna jack up the rear end and check for play and turn the wheels induvidually and see if there is noise and where it is coming from.

Vstahl

bet you will find the issue to be the rearend, a buddy of mine had a similar sounding trait and that was it. When he pulled the cover it was very obvious with the shavings and chuncks in the oil. His outer wheel bearing were fine it was the carrier and bearing that had grinaded.


Also, I am in Mckinney so let me know if I can be any more help to you.

91cavgt

Well, I pulled the rear diff cover off and it is perfectly fine inside accept for the nasty burned smell!! There wasn't even any metal shavings and the gears look good! So I jacked the rear end up, and there is no play on each of the rear wheels. So I jack the front end up, there's a little rotational play in the front, but the bearings are ok (no play in them or the tie rods). Both driveshafts are good and the u joints appear ok too.


However, I found something. The Jeep has 225/70/15 tires all around accept on the right front when it has 235/70/15 tire on it!!! Could this have damaged the transfer case? Would this cause the front and rear diffs to REALLY heat up enough to make them smell?

91cavgt

I just got finished changing out the rear diff, front diff, and the transfer case fluids. Here is what I found;

Rear diff - Fluid was badly burnt, smelled worse than what diff fluid normally smells. I can't put the drain pan in the garage like normal because the smell gets into the house. You can litterally smell the burnt fluid 30 feet away! The gears looked perfectly fine and there was ZERO metal in the bottom of the diff and no shavings anywhere.

Transfer case - The fluid smelled a bit burned and was a dark red, so I changed it. There was ZERO metal/aluminum shavings.

Front diff - The fluid was so thick it was like molasses!! It was a bit burnt, but not nearly as bad as the rear diff. Once again, there were no shavings and the gears looked perfectly fine.


Tomorrow after work I am going to try to find a used tire of the right size. All else fails, I'll put a new tire on it and later down the road replace the other 3 tires.


I also checked the tire pressures. They were all REALLY low. Pressures ranged from 24 psi to as low as 16 psi!! This probably made the situation worse. All tires were reset to 30 psi.

Vstahl

talked with a buddy of mine that has his degree in automotive engineers and is an engineer for ford and he believes that you might be on to something with your different sized tires.

according to him, the tolerances on a all wheel drive are so particular that different sizes from side to side can wreak havoc on a transfer case.

that being said, if you find that the transfer case is needing repair or replacement he and I both recommend going to a JY and getting a transfer case that is not all time. It is as simple as switching them out, being sure you get the linkage off the donor.

jblackmon421

I live in The Colony too. Let me know if you would like some help if you still have problems after replacing the tire. Sounds like it maybe the transfer case to me. If so there is a '93 at the pick n pull on 121 Business that you maybe able to get a replacement for cheap.

Jay