Should've left it alone....

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MopaR&D

MopaR&D

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When I rebuilt the top end on my 318 I replaced the rear main seal with the one that came in my gasket set. It was the two-piece rubber Fel-Pro kind with the two seals sticking out the sides of one of the halves. When I put it in I cut off those two seal things so that I could offset the halves which is recommended in everything I've read about installing rear main seals. However, since I got it running again it's been leaking a small puddle of oil from the back of the block every time I go for a drive and park it, so I think I did something wrong with the seal installation. I'm getting a new seal and already have the car up on jackstands, so how should I do it this time? Should I leave the two things sticking out of the one seal half, or cut them off again so I can offset the halves?
 
If you do leave the 2 things/tabs on put rtv under and on top of the tabs and 'seal ends' in general.
and to edges of cap.

And make sure the seal is oiled a lil so it doesn't burn up and leak.
 
leave them on and place a small amount of rtv where the little tabs go and a small dab between the two halves.
 
Alright cool, thanks a bunch guys. I'll be sure to do that when I assemble it.
 
hi, those things you cut off are to seal the main cap to the block to prevent oil leaks at the rear. they were put there for a reason!! off setting seals is for chevrolet junk!!
 
perfacar said:
hi, those things you cut off are to seal the main cap to the block to prevent oil leaks at the rear. they were put there for a reason!! off setting seals is for chevrolet junk!!
Click to expand...

Well the book I got on rebuilding Mopar small blocks shows (and tells) to offset the seal. BUT the example seal in the book didn't have those tabs.
 

The single biggest thing I see with leaky rear mains are there can be NO oil or grease on the surfaces where the seal hits the block and retainer, or the mating surfaces. Otherwise the oil will seep past the RTV in those little crevices and seep or leak like that. Also possible is putting 1/2 in backwards (or the whole thing like I've done before...). Go slow, be careful, use brake cleaner to make 100% sure everything is clean and dry, and it wont leak.
 
I have to agree with cleaning being the important part. A littlr rtv will go a long way while a whole tube wont help where oil is present.
 
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