Off Roading Forums banner
1 - 7 of 7 Posts
G

·
Discussion Starter · #1 ·
hi,
is there a way i can tell if my rear main seal is leaking or if it is the oil pan rear seal? i have just done the rear main seal twice since monday and it still leaks? what do you all think?
thanks
Matt

 
G

·
Discussion Starter · #2 ·
I assume its a 258 with a plastic valve cover? If so, check your valve cover for a rear leak. This has been discussed many times here, more often than not it is a valve cover leak running down rather than an engine seal. And one heck of alot easier to deal with. Clean everything off real good with degreaser, run it and see where the oil is coming from.

Brad
ORC Land Use Section Editor
http://www.off-road.com/land
Vice-Pres. Rock Garden 4 Wheelers, Farmington, NM
http://rockgarden.rockcrawler.com
 
G

·
Discussion Starter · #3 ·
yes its a 258 but it has an aluminum valve cover. i can see the oil come out of the very back of the oil pan, i was just wondering if you could tell if it is the oil pan or the rear main that is leaking
thanks
Matt

 

·
Registered
Joined
·
13,432 Posts
Jeep8719, it's not unusall to do the job twice or three times. If you're a novice at this job I'd expect this to be the norm. Did you loosen up the main bearing caps a little to let the crankshaft drop a little? This aids in removal an reinstall of the seals. Or did you keep the crankshaft in postion?

If you did not drop the crank a little, I'd advise it... it's much easier. You just have to have a torque wrench to tighten the caps back to spec. Then use enough gasket sealer on the oil pan to sink a battle ship in the rear main area. Let it setup a couple of hours before you refill with oil.

 

·
Registered
Joined
·
521 Posts
also....
does the seal surface on the crank itself have a groove worn in it? if this is hi-milage or hi-wear engine it might. this groove will prevent a good seal. only fix I know of is to remove the crank, weld the groove full then re grind bearing surface. almost might as well re-build at that point, eh? I had a 258 like that once and dealt with the slight leakage.
can't remember for 100%, but I'm mostly sure the block and brg cap mating surfaces need to kept free of any sealant to maintain proper brg clearance. sealant between these surfaces could also lead to poor seal.

sorry for these but I hafta ask -
did you put the seal in the right way... so oil pressure forces the seal lip against the crank seal surface?
did you use a torque wrench? ...and tighten the bolts in sequence progressively, so gasket and sealant will be compressed evenly but not pinched out?


 

·
Registered
Joined
·
521 Posts
sorry
to answer your actual question...
I think you can remove the cover which closes off the bottom portion of the trans (just a few bolts) and peer up with a flashlight between the flywheel & oil pan. like Leve said, clean it all off first. way easier to see where the oil is from.

 

·
Registered
Joined
·
1,271 Posts
Been there, done that (as I recently explained in the "I hate projects" post). I am currently on go-round # 3. Having similar problems, my leak is on the rear, up on top of where the starter mounts, at the back passenger corner of the oil pan.

I have to ditto Leve's bit on the RTV, gunk it up good. A couple of other steps from the Late Great Willy Worthy too:

1) Tighten it up just enough to make the RTV squirt out the sides. Wait about 15-20 minutes. Then torque all bolts to spec.

2) Torque specs on the small bolts are 7-9 ft/lbs. On the bigger corner bolts it is 9-13ft/lbs. Get a torque wrench and use that thang! Make sure you are in torque specs on the bolts.

3) Let it cure for 24 hours before using. Hit pan with big rubber mallet to seat and re-torque all bolts.

This got 95% of my leaks, I think the other 5% I'm seeing now are just excess dripping off the frame/parts. Keep your fingers crossed for me.

'83 CJ-7 nothing original but the tub and axle tubes
 
1 - 7 of 7 Posts
Top