Rear main seal

[TwistedCU]

Well I am done modding the XJ for a while. Now I'm looking at getting the YJ into road worthy condition so I can put it on the road.

First things first. The oil leak. It is probably the worst oil leak I have ever seen. Oil literally drips, bordering on pours, out between the motor and transmission. The guy I bought it from more or less botched up an attempt to repair it, and probably just complicated the problem.

Without a garage and on a limited time schedule, I think I am going to pay to have it done. Before I take it to someone, can anyone give me a ballpark figure to what I should expect to pay for a rear main seal? it's an 88 YJ 6cyl 5 sp . Am I over-reacting to this job being too much and should really be doing it myself? I've never done any major engine work other than my buddy's old VW bug (no comparison).

My biggest fear is that the dude may have hacked up the area trying to get the old seal/gasket off. If this is the case, what would be a solution... machining? new motor? either way I'm afraid it could get ugly :roll:

 

[Ritt]

Are you sure it's not the valve cover because just about all of them leak especially if its pouring out. Both my YJ and my wifes ZJ leaked the same way. My wife's was smoking up a storm because it was running onto the crossover pipe. Both were 4.0s. Both cases the rear screws on the valve cover were loose. It's an easy repair, new gasket and RTV. I did have to buy a flexible 1/4" socket extension from Sears.

 

[Joopin]

My YJs rear main went too, I brought it to get fixed, and they thought what Ritt was saying that it was the valve cover. I told them "fine your the experts" they cleaned the whole engine, replace the valve cover gasket, and it still leaked. They apologized that they didn't listen to me the first time and gave me a break on the rear main seal repair. I think they charged me around 200 bucks. If you don't get it fixed right away it could damage the other crank shaft bearings which can't be replaced unless the engine is apart. I waited too long with mine and the rear main is leaking again. So now I am just waiting for it to go so I can stroke it out during the rebuild.

 

[LRwrnglr]

I replaced mine in my YJ not too long ago and fixed the leak for good, well for right now anyway. I cant remember how much the seal was but it wasnt anything too pricey, anywhere from like 10-50

 

[TwistedCU]

I do know for a fact the guy I bought it from had it apart and did not replace the gasket properly. I posted the story a long time ago, but basically the dude only got half of the gasket off and cut the new one to fit what was still stuck on there. He said he sealed it and thought it would hold :roll: . It was leaking as soon as he fired it up 2 days later (big surprise). This is why I know the rear main seal needs to be replaced.

That said, it is possible the valve cover was the whole problem to begin with and he did all that crap for nothing. It would not surprise me a bit. I'll check the valve cover and replace it if needed (I know that one is easy), but I still want to address the rear seal 'cause I know it is half-assed.

A buddy of mine said he has his done at the stealership for $600. His is an automatic. I certainly don't want to put out that kind of cake for it though.

 

[Ritt]

This looks promising...

I don't think there's anyway to do it w/o pulling the transmission/t-box back. I'm changing the seal on the Willys when I pull the transmission/t-box and install the used set I just bought. It's always worth it to me to change the clutch even if it hasn't been there long enough to ware out. I hate doing things twice.

I would take a look first. You have to remove the rear cap and the next 2 have to be loosened a little to take the pressure off. There is a removal kit that auto stores sell with the cork screw to pull the upper half. The other way is a stiff thin wire with a slight curve in the end. Feed it up through the old upper half until it comes out the other side. Bend a little hook and pull it back out. Works most of the time. I clean the channel out with brake cleaner and a long piece of rag.

I bet he never remove the old upper half or did a sloppy job of putting it in. Some times you can do your best and it'll still leak.

 

[TwistedCU]

That's exactly what he said, that he didn't ("couldn't") get the upper half off. Why he put it back together that way I'll never know.

 

[90Xjay]

Some people have screwed up the gasket mating surface by gouging it with a pick or awe in removing or reinstalling the seal.
That can cause a leak, but usually not the the extent you are expaining.
If that is the case, some polishing with emery cloth usually is the fix.
But like the other post, don't overlook those valve covers. Mine started pouring out just right after I bought it and when I took the factory gasket out, it was harder than your mother-in-law's heart and was leaking bad.
Valve cover r+r, about 2 hours and yes that rear bolt is a booger esp if you have big hands. Good luck!

 

[TwistedCU]

it was harder than your mother-in-law's heart .

So basically it was like teflon...

You'd have to meet my mother in law to really appreciate how true that statement was :lol:

I really hope the wife doesn't read this stuff :twisted:

 

[Joopin]

to get the top half out you have to push one end with a screw driver or something like that, it will then come out the other side and you pull it the rest of the way out. Then put in the new one the same way. When they replaced mine they did not seperate the transmission from the engine.

 

[Snitty]

is it possible to do through the oil pan?

 

[laneiac]

I am pretty sure you just pull the oil pan.

 

[Joopin]

Yes, just pull the oil pan.

 

[LVRockCrawler]

RE: Double WHAT ?

I cant believe this is here tonite... i was going to post and ask about the same thing... mine is leaking like crazy and driving the wife mad w/the oil puddles! so you can pull the pan and just do the tap/pull for the top half and call it good?!?! (gotta find my manual - lost in the move...)

 

[Saurian]

My rear main is seeping on my XJ. Went to the good persons at Birmingham Chrysler-Jeep, they let me know that it would be somewhere in the neighbourhood of $680.00 to replace... I got the CD changer fixed instead, figured for that kind of money, I'd better be losing GALLONS of oil before I get it done...

 

[TwistedCU]

I'm guessing this is what this guy, we'll refer to him as "dipstick" from here on out, tried. He said the gasket was baked on solid. Still think it can be done via the oil pan? I'm going to be entering unchartered territory here, so any info/link may be helpful. It may take a look at it this weekend and give it a go.

oh yeah, don't forget I have the older 6 cyl and the BA/10 transmission if it makes a difference.