I never see this addressed in any of these threads... The most common source of leakage at the rear main is the contact area between the retainer and the block. Turn the seals like Monte said, put a dab of your favorite sealer on the mating surface of the retainer, and pay close attention to the side seals. Seems to me the mating surface is never mentioned.
I would assume everyone knows the retainer has to be glued on final install. My point was that too many pay too little attention to retainer and just bolt it down. The retainer, how and where it fits is really of little consequence as long as the seal is straight and fits right, but people don't check it. They always think the seal is the problem. A lip seal is very simple and nearly always works IF you get it straight.
Not saying my way is perfect or the only way.........just that I have always done it this way and my rear seals don't leak. Can't recall ever having a problem with a chronic leaking rear seal. The next one I do may leak like a sieve, but I doubt it
