So I bought this 92 Cherokee awhile ago for like $500. Thought ok a lil tlc and it'll be good, welp I've been having a persistent problem with the oil leaking out from the back end of the oil pan. CCV valve has been replaced and have recently replaced the oil filter and completely replaced the oil pan after doing the gasket 2 times. Also the rear main was recently replaced. Any ideas where this leak could be coming from? It's coming from somewhere and running down the front end of the trans and then the ground. Any ideas would help as I'm tired of filling it with oil every couple hundred miles... -_-

 

In some cases the early Cherokees have this problem, which may be why yours was for sale cheap. It may be that the crankshaft is moving destroying any rear main seals. There is a thrust washer that is supposed to keep the crank from moving back and forth. In other words, it may be cheaper to replace the engine than to fix the problem with yours. You do need to confirm it is in fact coming from the rear main seal though. Common leaks are valve cover gaskets and oil filter adapter seals. Since the bell housing is the lowest point, a lot of oil ends up there even if it didn't start from the rear main seal.

 

New gaskets don't always mean the problem is solved. The rear main seal could have been damaged or installed wrong, same goes for the pan gasket.

 

Well it's also a reconstruct with 226k on the motor and trans lol... But I'll look into it a bit more and see if I can't find indefinitely where the leak is coming from and fix accordingly. Thanks!

 

One piece oil pan gasket?

 

Yep, we did the gasket once with rtv and the leak was worse

 

Not surprised.

 

Like MD mentioned, you need to be darn sure it's not the oil filter adapter O rings. It blows right back and mimics a bad RM seal.

 

To update, the oil is definitely leaking out of the rear main. Gonna start looking for a new motor to put some work into before dropping it in. Probably is due for a swap anyway having 225+k miles on it. Thanks for y'all's help!!

 

A rear main seal is a lot cheaper than a new engine. 225k is barely broke in.

 

I agree 2 tone. One of mine has 200K and a leaking RM, never even considered anything but changing it.

So you got under there with it running, cleaned around the adapter and are positive it's not leaking. Can be tricky! Oil can run back from there to the rear really fast.

 

Yea I got under it while runnin and it was more than dripping out of the RM... Found a new motor for $300 tho

 

That certainly sounds easier.....

 

Even better is it's an older 4.0 from a 90 Cherokee, so it's got bigger bores than the one in it now, plus I'm swapping in a high output performance head, performance plugs and wires, and performance fly wheel.

 

Respectably, you are not gaining anything except an expensive headache. I'd try replacing the rear main. If the leak quits, then comes back after a while you might suspect the bearings have worn enough to let the crank move down a tad, but the 4.0 about doesn't do that.