Hello folks need some help here. I've read pretty much every thread that has "leak" "rear" "main" and "seal" in them and have not come across anything that really touches on what I've got going on here.
I just put in the second, brand new Rear Main Seal (RMS) on my 1990 Jeep Cherokee 4.0. The first one went in from the rear, since we had to replace the freeze plug that is on the rear end of the engine, plus it was leaking oil from the seal as well. Anyway my mechanic installed the seal while we had the transmission out of the vehicle. The first one obviously, did not seat correctly as she still leaked oil after we put her back together. So we pulled the “new” RMS out (through the oil pan this time) and it was hard, black and not much rubber left on it at all. Now, we just installed the second rear seal and put everything back together again and NOW, it is leaking WORSE than it did with the original one... I mean the oil almost comes out of the seal as fast as I can pour it in (not really but I hope you get the dramatic license). Anyway, any ideas as to what might be going on? We are doing everything by the "manual" (Chilton, I think) but by all counts, it SHOULD be sealing but it is not. Does anyone know why?? I just sank a BUNCH of $$ into her over the last year or so, tranny, gaskets all around, suspension (prety much stock replacement). I've got an entry level vehicle and want to go up but now we're dead in our tracks.
I will thank any and every one in advance for any ideas or directions we should go,
Thank you,
Desperate‼

 

What? Im lost? What do u mean u relaced the seal thru the rear, and then through the oil pan? Theres only 1 way to do a rear maní seal. Just Trying to figure out what u did ...

 

You didn't install it backwards did you?
That would explain the complete failure.

 

This is the part that is confusing me.

 

did you use sealant in the proper spot? score the metal in any way?
Changing the rear main seal

Jeepin.com » Replacing your rear main seal

 

Thank you ALL for getting back so quickly. To be honest as for the "rear" thing, I was not present for that proceedure. I got the freeze plugs in and the cham access plug in but my buddy installed the RMS while I was taking a breather. When I got back, the flex plate was on and we were ready to start puting her back together. He told me that he had "a little issue (whatever that means) but all-in-all the Seal went in pretty easy.

As for the sealant, yes, according to BOTH book and part instruction the sealant went where it was suppose to...

And yes, I agree, if it went in backward, then that WOULD completely explain the situation BUT that one has already been removed and the "new(est)" one went in (confirmed) correctly....

I hope that clarifies all of the above questions... and I even more so, hope that it helps.

Thanks again!!

 

The RMS was installed from the "rear" of the engine, with the transmission, flex plate, etc removed. As below, I was not present for this portion of our "operation" but as for "from the front" I meant just pulling the oil pan and removing the RMS via what I'd call the "normal" way. eh? I do hope that makes more sense.

 

The only reason i asked is the "ONLY" way to get at the seal is to remove the pan and then the rear main cap ... Ok anyway on the second one did u make shure u cleaned all the old seal out before Installing the new seal?

 

sealant "yes" as for scoring, no to my knowledge. It was removedas gingerly as applicable (no screw drivers, framing hammers, etc.) heh!

 

And ur shure Its not ur oil pan gasket leaking at the rear? I ask questions not only to get a better idea of the problem but to make shure Its the rear main seal.

 

yes, completely cleaned with new, clean rags and no lint left behind....

 

No-offense but I think your buddy lied to you. you can't do it any other way other then pulling the oil pan, rear main bearing cap ect...

you replaced the oil pan gasket? sure its not leaking from the pan in the back? back of the valve cover dry? it can drip down and look like a rear main, I've seen people do that. If the seal is facing the proper way, everything was cleaned, and you used sealant under the cap it should seal just fine.

 

yes, brand-spanking new (blue rubber/metal) one piece oil pan gasket. She's sealed in that regard, sweetly. I am as close to 100% sure that the MS is leaking, like in the 99.99998% range. (trying to put SOME levity in this, heh)

 

Ok. Im at a loss. Im goin to back out. Maybe Someone else has more knowledge than me on this one. ( i just did my rms a couple weeks ago )

 

Well, from what I am starting to understand is that you may br right (nobody likes to admit they've been "smoked") but I am startring to question wheather he replaced the unit or not. As far as I can remember, we never had the pan gasket off for the tranny swap/freeze plug/cham access proceedure.... I'm starting to scratch my head at this point....