'89 XJ rear main seal?

Deereman

Well-Known Member
Joined
Jan 5, 2008
Location
Archdale
:confused:I have an 89 XJ with the 4.0 in it. When I aquired it I was told it had a new rear main seal in it. it leaked bad for like a week after I got it and then stopped. Now it leaks like crazy. I'm new to mechanic'n on these things. I heard that some of these have 1 piece seals and others 2 piece. I am going to try to put a new seal in and any help/tips would be appreciated.
 
i havn't done an 89, but the ones i've done were all 2 piece seals. be carefull. you don't want to score your crank.
 
The 4.0s are known for that. I think the older 4.0s were 2 piece seals. Should be a pretty messy job :) You'll probably have to pull the oil pan and will need a gasket for that also. There are a couple of tricks to getting the top part of a 2 piece seal in without damaging it but if you do other mechanical stuff on your rigs it shouldn't be too much of a problem.
 
I did one on a YJ. Wasn't all that bad, just messy. The bad part is, since it's a 4.0l it will probably start leaking again down the road. Good luck.
 
I would make sure it was not the valve cover gasket leaking from the rear of the motor and running down the back. You would swear it was the rear main seal. If the seal was changed, I would bet that is your problem. If it is the problem, it has a 2 piece seal that is easy to change...once you get the pan off.
 
I owned this jeep for a little while...I was told it had just had one done. Couple days later boom........oil. No biggie its a 4.0 they blow rear mains. Ended up trading it before i fixed it. The guy i traded it to said someone had put the seal in wrong...my guess is they reused the old seal when they saw it was put in wrong.

my advice is go slow and take your time. Its not a hard job just a little frustrating. Goodluck.
 
Hey, I'm going to try to put this rear main seal in this weekend and I heard some talk about using diesel oil in a jeep because its thicker. Has anyone ever done this or heard if it's a good idea or not?
 
I dont know about running it because its thicker, but deisel oil has a zinc additive that helps increase the life of some of the internal engine parts. It also helps keep engines from sludging up on the inside. Its a great choice for the 4.0.
 
You would also need to check the oil filter adapter seals, often mistaken for a rear main seal. X2 on checking the valve cover especially if there is a gasket there, should have been RTVed in place.
 
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