murfanater

I need to replace my rear main seal on my 1989 jeep comanche 4.0 6cly. I got the part but need to know the easiest way to replace it. i have to right tools so just say them as you give directions. I def would love pictures so plz o plz put them up they help me so much! all the steps and picture would help a ton thanks guys you always seem to get my jeep running and dont disapoint thanks alot.

ss427ci

Search my friend

https://www.cherokeeforum.com/f2/rea...lacement-4426/

47 posts in this thread so there should be some good info and a 91 cherokee I imagine would be the same as your 89. Don't know for sure though.

Bustedback

I would do the valve cover gasket, oil filter adaptor orings, and distributor gasket before dropping the pan for the rear main, which may not even be the leak.

ss427ci

^ x2 or at least clean it up real good and see if you can trace the leak somewhere higher.
I'm about to replace my oil filter adapter o-ring.

Cherokeekid4x4

Check everywhere but don't get your hopes up on It being something simpler, everyone told me to do all this stuff when it really did turn out to be my seal. Going to replace that along with oil pan gasket next oil change.

highmileage

About the best thing you can do for yourself if you have to do the rear main is to put a jack under the front Xmember and get the axle as far away from the pan as possible.

cruiser54

For MANY more than just you, it HAS turned out to be something else.

The OP needs to diagnose HIS vehicle that he can SEE and come to the correct conclusion.


Here's how.




　

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

murfanater

do i have to drop the transmission to fix the rear main seal?

murfanater

http://go.jeep-xj.info/HowtoRearMain.htm

Bustedback

You're just dead set on doing the rear main, aint ya? No, you don't need to drop the transmission.

Cherokeekid4x4

Let me get the link to the website with a very detailed write up one sec

Cherokeekid4x4

http://jeepin.com/features/rearmain all you need is right here.

murfanater

I was able to fix it! no more leak! to get it in there though oil the hell out of it cause it is a tight sqeeze

Muaddib420

Good job.

Cherokeekid4x4

X2 way to go.