Rear Main Seal questions

[Al Lindner]

I got my 1980 CJ7 back on the road! BUT its leaving a puddle in my shop. I've read about the Valve cover gasket (AMC 258 i6 / 4.2l I6) mimicking a seal leak.
Here is my question. Wouldnt the fly wheel be oily? There is slight oil in the bell housing but MINIMAL. The back side of the flywheel (side facing the block) is DRY. Should I change the seal or let it ride? The pan is off and I'll be installing a one piece rubber gasket should I use any gasket sealer?
I know its more than one question but any advice would be greatly appriciated Thanks guys

 

[jamesweed]

I like many had this leak, it originated at rear of valve cover and and ran down rear. I didnt have much oil in the Bell housing, but I was "tricked" in to changing rear main seal. If youve got an old plastic valve cover, change to an Alum. one, not a bad job to change valve cover gasket, much easier than that oil pan one for sure. While youve got the pan off, i would change the rear seal just to eliminate it. Its a cheap part and fairly easy job since youve got the pan off., I used a bit of RTV sealant at front and rear of pan, as the rubber gasket left some small gaps around bearing cap when i test fit it, IMO doesnt hurt anything, a year later Ive got no leaks.

 

[Al Lindner]

I was leaning towards replacing the seal but the motor is a remanufacture with VERY low hours (less than 5). While its POSSIBLE the rear main is leaking, I doubt I could do a better job installing a new seal on my back under the jeep. After finding the DRY flywheel my gut is to reinstall the pan with the new 1 piece gasket and redo my steel valve cover ( check the head bolts while its off)

 

[PaRenegade]

I was going to ask but with that being said, your right chances are the rms isn't the culprit. I'd replace the valve and pan gaskets with a good FelPro gasket and go from there. I almost always use at least a little bit of sealer on gaskets. The trick is, especially on the pan and valve covers is to put down you bead and gasket(s), both side won't hurt, apply the cover/pan and snug the bolts up but don't tighten them yet. Let it sit for an hour or two or even overnight, then torque them to the correct spec. Clean surfaces are key as well. A lite sanding with some emery cloth after the gasket has been scraped away. Then wipe the surfaces with some lacquer thinner.

 

[rockinreel]

I had a valve cover leak at the back of the valve cover and oil was every where... All over the Transmission and Transfer Case to boot! (because of highway winds).

 

[Tommy]

I've posted this before. There is a product called "The Right Stuff". Use it instead of a gasket. You can get it at most any automotive shop. I had the leak at the rear of the the valve cover. Went through replacing the rear main seal and putting on different types of gaskets for the valve cover. Nothing seemed to work until I found this stuff. Two years without a drop since I used it. Just follow the directions and you are good.

Tommy