I replaced my rear main seal 6 or 7 months ago and still had a small leak. The weather cooled off a bit and now it is leaking a little more. I've done the valve cover gasket and the oil filter adapter seals and am certain it is not leaking from those areas. I think that I probably screwed up the oil pan gasket where it seats on the rear main bearing cap. My question is if the rear main were bad wouldn't there be oil slung on the inside of the bell housing and on the flywheel? Should i just go ahead and do the rms since I'll have the pan off again?

 

Same thing happened to me.

I think they're just designed to leak. I live with it.

 

I thought he meant Root Mean Square, as in 120 volts RMS. Silly me.

One thing you could try is to get a real torque wrench and hit the pan bolts, starting at the middle there and working out. You would be surprised how loose they might be. Offhand I think the spec is 21 ft lbs but PLEASE check that I don't want to be responsible for a stripped bolt.

 

There are two size fasteners for the oil pan, 1/4 and 5/16. Some are studs. Neither get torqued to 21 foot pounds.

1/4 - 84 INCH lbs., or 7 ft. lbs.
5/16 - 132 INCH lbs., or 11 ft. lbs.

 

Got the pan out and the pan gasket was a little cut up where it fit into the rear main bearing cap. Does anyone know if the fact that there was no oil in the bell housing or on the flywheel is proof enough that the rear main is okay or should I just go ahead and change it since I'm in there?

 

That little dribble doesn't look like RMS to me. I would personally suspect just the oil pan. I would say your judgement since the rms is cheap but 7 months is an awfully short life for one

 

Here we go again:

I’d be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn’t own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don’t jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons:

First off, the engine sits nose-up and any oil will run back to the RMS area.

Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber’s adage apply here: “Crap flows downhill”.

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.