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Rear main still leaking!

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NAXJA Forum User
Location
So. Central Indiana
My son and I just finished doing a rear main seal in his 89 xj ( 4.0 aw4 ). We started the jeep and let it idle for about 10 minutes with no leaks, then he took it around the block to talk to a buddy and rolled back in the garage with oil leaking out the rear main again, A BUNCH.
I have found my Chiltons manual and the only thing I see that I might have done wrong is not putting RTV on the seal or around the edges of the cap itself. Do you think this is what is causing the leaking?????
 
digger4u said:
My son and I just finished doing a rear main seal in his 89 xj ( 4.0 aw4 ). We started the jeep and let it idle for about 10 minutes with no leaks, then he took it around the block to talk to a buddy and rolled back in the garage with oil leaking out the rear main again, A BUNCH.
I have found my Chiltons manual and the only thing I see that I might have done wrong is not putting RTV on the seal or around the edges of the cap itself. Do you think this is what is causing the leaking?????
Click to expand...

yep without the rtv it runs out around the edges like a seive. time to take it apart again.
 
xjnation said:
time to take it apart again.
Click to expand...

That sucks. I was going to tackle my rear main this weekend. Any poiniers??? I dont understand the part about the "SOAP" is that talking about actual soap like hand or dish soap?
 
I use rubbing alchol to totally clean all mating surfaces. also the RTV sill stick better. let the RTV skin over before you reassemble it too. just take your time and follow the destructions. also a feeler gauge works great for pushing out the old seal upper half
 
Man that SUCKS a bunch. Oh well i got the fancy rubber gasket for the pan so that should still be good and the seal itself should have no damage, so just drop the pan AGAIN and the bearing cap , RTV it and shove it all back together. 10 minute job Oh well I guess we chock this one up to a father, son bonding night and try again tuesday night.
 
digger4u said:
Man that SUCKS a bunch. Oh well i got the fancy rubber gasket for the pan so that should still be good and the seal itself should have no damage, so just drop the pan AGAIN and the bearing cap , RTV it and shove it all back together. 10 minute job Oh well I guess we chock this one up to a father, son bonding night and try again tuesday night.
Click to expand...
make it clean clean clean first
 
I did the rear on my 87 twice, the first time I forgot to lub the new seal up good with grease or assembly lub. Slap forehead and let out a string of four letter words here. I know better than to install a dry seal and hope it oils itself before it gets hot and wears a bunch.
Might also want to pull the rear cap and take a look at the main bearings. A set of plasti gauge will tell you quick if it´s very worn. If the mains are very worn, the seal usually doesn´t last longer than 3-6 months before it starts to seep again.
Eagle mentioned that there is a double ridged seal out there someplace. Helps the main seal, to seat in a slightly different spot and helps with the seal. I haven´t had very good luck with Fel-Pro, next time I´m gonna go OEM or find a double inner ridged seal as a replacement. To darned much work and mess to try and cut corners.
 
You might also want to check your valve cover gasket. I replaced my rear main seal, only to discocer that my v.c gasket was leaking as well. I never thought to check the v.c because it didn't appear to be leaking-but it was leaking very badly in the rear, where I couldn't see it,running down to the same area that the rear main was leaking. So as it turned out in my case both seals were leaking.
 
xjoe said:
You might also want to check your valve cover gasket. I replaced my rear main seal, only to discocer that my v.c gasket was leaking as well. I never thought to check the v.c because it didn't appear to be leaking-but it was leaking very badly in the rear, where I couldn't see it,running down to the same area that the rear main was leaking. So as it turned out in my case both seals were leaking.
Click to expand...

This was my thought too.

B-loose
 
8Mud said:
I did the rear on my 87 twice, the first time I forgot to lub the new seal up good with grease or assembly lub. Slap forehead and let out a string of four letter words here. I know better than to install a dry seal and hope it oils itself before it gets hot and wears a bunch.
Might also want to pull the rear cap and take a look at the main bearings. A set of plasti gauge will tell you quick if it´s very worn. If the mains are very worn, the seal usually doesn´t last longer than 3-6 months before it starts to seep again.
Eagle mentioned that there is a double ridged seal out there someplace. Helps the main seal, to seat in a slightly different spot and helps with the seal. I haven´t had very good luck with Fel-Pro, next time I´m gonna go OEM or find a double inner ridged seal as a replacement. To darned much work and mess to try and cut corners.
Click to expand...

Pam spray works really well for seal lube, hi temp and wont wipe off quickly
 
If you open it up to do the job again, look closely at the crank surface to see if the old seal wore a slight groove. You can buy a replacement seal with a double lip that seals even if the crank is slightly scored.
 
xjoe said:
You might also want to check your valve cover gasket. I replaced my rear main seal, only to discocer that my v.c gasket was leaking as well. I never thought to check the v.c because it didn't appear to be leaking-but it was leaking very badly in the rear, where I couldn't see it,running down to the same area that the rear main was leaking. So as it turned out in my case both seals were leaking.
Click to expand...

The valve cover gasket does a better impersonation of a rear main seal leak than the rear main itself does...I had a bunch of oil down there and just ran a socket wrench around the VC bolts, few loose ones sure enough, snugged em back up and now it's much drier...
 
Well another great night under a Jeep!!! My rear main seal is in good shape, no nicks, cuts, or other wise bad things, and the rubber gasket is still in one peice and still looks good. When I get back at this to finish what is the best sealant to use to basically glue the pan gasket to the small valley where there is no bolts.( I have the one peice rubber pan gasket with the metal around the bolt holes). That would be in the rear over the seal.
 
89XJ is right, the crank case pressure will cause oil to leak out of the rear main seal. The pvc valve can clog and build up the pressure. Good luck.
I'd use the black stuff for sealant.
Stukboy
 
Just did mine this past weekend and no leaks so far. I wasn't in there to replace the seal though. The oil pump locked up and stripped the teeth off the dist gear. At least the motor stopped running and prevented any major damage.

It took all day to get it on the road again. No leaks though. I installed the double lip FelPro seal from Advance, new Melling HV pump and rebuilt disty (The shaft was chipped on the end).

10 minutes? You have got to be kidding.
 
Stukboy said:
89XJ is right, the crank case pressure will cause oil to leak out of the rear main seal. The pvc valve can clog and build up the pressure. Good luck.
I'd use the black stuff for sealant.
Stukboy
Click to expand...


xj 4.0's don't have a pcv to clog.
 
bzdel2441 said:
That sucks. I was going to tackle my rear main this weekend. Any poiniers??? I dont understand the part about the "SOAP" is that talking about actual soap like hand or dish soap?
Click to expand...


use dish soap when u put in the new seal, it helps it slide around a lil better
 
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