2 piece rear main seal advice

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1low4x4

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Guys I think ive got a leak from the rear main seal, not sure but going to pull the dust cover and look around. I bought the good Felpro blue gaskets. Ive read some stuff about how they never really seal up. Will I be wasting my time doing this or should I give it a go. Ive heard all kinds of things from rotating the halves of the gaskets so the ends don't mate up exactly with the block/pan surface, to using a dab of silicone on the edges, etc. Any advice would be good. Thanks
 

1987 GMC Jimmy

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I've heard all the things you've heard. The only suggestion I can offer is to be sure that it's not the rear portion of the oil pan seal because those like to leak sometimes, plus they look and act similarly when they leak. The only comfort I can offer you is that at least it's not like changing the rear main seal on a Gen III small block.
 

74 Shortbed

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IF the rear main seal is leaking you'll have to drop the pan and the rear cap, rotate the block half out, it can be a PITA sometimes but it will come out, reverse for installation just make sure the lip faces inward same for the cap, DO NOT use silicone on the ends it'll be all over the crank, you can use a dab of gasket cement but you don't need anything for them to seal, re torque the cap and put the pan back on and you're done..
 

87scotty

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And from what ive heard... So take it as a grain of salt but usually when rear main starts leakin your do for a rebuild. Do to crank thrust! Like i said idk if i belive it but makes since if its sliding back and forth taking out seals
 

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A seal will fail from sitting too long and dries up and sticks to the crank, when you start it up it grabs the seal and ruins it, also excessive heat will harden the seal and make it leak, badly worn main bearings let's the crank move around and will cause the seal to leak, a bad thrust will allow more end play but won't cause a seal to leak
 

1low4x4

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Thanks for the insight. Im not worried about it needing rebuilt, I may get to this today
 

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