Jeep Cherokee Forum - Rear main seal

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Has anyone change the rear main seal without taking the tranny out which I watch a video on utube doing this. I wanted to no what was the torque specs for the first cap closest to the tranny. Any info appericated

U don't have to remove tranny. Just remove the oil pan. I took the rear cap off and loosed the 2 in front of it. Should be enough room to push out old seal and push the new one in. Make sure and put lube or soap on the seal to help it. I have a 3" lift and had to remove track bar and sway bay to get enough clearance to pull oil pan. It's pretty easy to change just take your time and don't rush it.

Quote:

Originally Posted by Blacksj (Post 2286619)

Have YOU VERIFIED it's the rear main leaking?

　

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. "$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 9-15-2012

Quote:

Originally Posted by cruiser54 (Post 2287195)

Agreed^^^ make sure you check everything first.

If you do have to change the RMS, it's not that bad, and you do not have to separate the trans. I bought 2 just in case and ended up screwing up the top half of the seal the first time. Hardest part if the entire thing for me was getting the oil pan off.

I just replaced my rms on my 99. I have a 3" lift and the worst part was getting the oil pan out. However, i didnt have to remove the track bar or the swaybar. You will need a small punch or screwdriver to get the old seal to start moving. BE EXTREMELY CAREFUL NOT TO SCORE OR NICK THE CRANK. I did mine in just a couple hours and had cleaned everything. If your mechanical you shouldnt have any problems.

Is there a certain torque specs to the cap bolts.

Had the same issue. Thought it was rear main and bought the new seal and oil pan gasket. Decided to power wash the engine and really look around to be sure. Turned out to be valve cover gasket + oil filter adapter. Interesting thing was that they really didn't start leaking until I changed the oil and added Engine Restore additive.

Quote:

Originally Posted by 95XJ_CBiscuit70 (Post 2294999)

Common outcome. That's why I wrote this:

　

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. "$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 9-15-2012

Make sure you offset the seal too. Meaning too leave about 5 mm hanging out ao it is not in line with the bearing cap break!!! I made that mistake and was leaki g after 5000 miles. Also some rtv never hurts!!! Torque girdle in order too

Just replaced my RMS didn't have a torque wrench now there is a loud squealing/ grinding coming from that area no leaks flywheel/starter looks good anyone know what happens if you over tighten the bearing cap?

Quote:

Originally Posted by ianridlon (Post 2896456)

Please tell me this is a joke.
Dedicated to Salad

Thanks dick. Guess I'm buying a torque wrench.

Quote:

Originally Posted by ianridlon (Post 2896808)

Thanks dick. Guess I'm buying a torque wrench.

His name is Slim.

Those main caps torque up pretty high. Can't imagine you overtorqued them by accident. Use an impact or anything?

Just a wrench. Took it back apart(couldn't get it off with the same wrench) and the cap looks like it was rubbing a bit didn't have it running long. Good excuse to buy a torque wrench.
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