Author Topic: 4.0l rear main seal (Read 1445 times)

frenchy · « **on:** November 14, 2007, 12:17:21 AM »

Notorius for leaking, sometimes a pain to replace, bring it to a shop and you pay a fortune to fix...

I've only ever seen them leak out onto ground below.
My question is this... what does it actually "seal" ?
Can oil leak anywhere else other then out ? has that ever hapenned?
If a person were to jbweld it, or otherwise block it completely from leaking out, what would happen ?

Waytec · « **Reply #1 on:** November 14, 2007, 01:22:23 AM »

The rear seal seals the crank shift and your transmission is indirectly connected to it and it rotates at engine speed. The oil can only leak out. The seal is around the crank shaft and the bottom end of the engine is behind it. The only way to fix it, if it is bad enoph that it’s leaking on the ground is to change it. You can not repair it.

cablesmurf · « **Reply #2 on:** November 14, 2007, 07:16:02 AM »

It is a very messy job to change, and I couldn't be bothered with it. I'm taking mine into Modern tomorrow to have them change it. For the record, they quoted me almost half what Canadian Tire did.

Here's a write up if you want to do it yourself.

http://jeepin.com/features/rearmain/index.asp

frenchy · « **Reply #3 on:** November 14, 2007, 08:07:54 AM »

The one in my old XJ was quite easy to replace, but one from a friends XJ, not so much. Now's the ZJ's turn... :x

Guess you can't just stuff the outside area full of sealer to stop it from leaking.

I was thinking the entire bearing cap is covered by oilpan, so oil must be leaking from somewhere else...
but the oilpan actually only covers the bottom and front of the cap, leaving the back exposed and oil to leak out between the cap & crank, correct ?

rws · « **Reply #4 on:** November 14, 2007, 08:18:57 AM »

Not a difficult job but real messy.