Hey folks. So i have this leak coming from the the bellhousing on my 89, 4.0 xj. the block is dry around all common leak areas. I changed the RMS twice and the problem continues. I didnt pull the tranny to change, but should i have? The leak comes down inside the inspection plate to the bottom bolt and forms a drip. I cant really drive it cause the oil blows on the exhaust and smells up the cab. Got small kids so i dont drive it much. So to conclude, i could really use ANY advice to solve this problem. And, should i pull the tranny to find the problem? Thanks

 

I would double check for other leaks before going back to the RMS. Make sure that the valve cover, oil filter adapter and the distributor aren't leaking. If those leak it can make it look like it's the RMS. Because all of the oil will run down to the rear of the engine looking like the rear main. And if those are are fine you didn't install your new seal correctly. BTW, You don't need to remove the trans to change it.

 

Thank u for the advice. What made me think it was the RMS was how quickly the drips would form under the tranny. As soon as i park the drips start. Plus the other possible leak areas are dry.

 

This explains how YOU can diagnose your oil leak(s) accurately.




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, people on Jeep forums who can’t see your Jeep from where they’re at, 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. "$hit 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.

Revised 02-26-2013