From: aj253@rgfn.epcc.Edu (Tony Robinson)
Several reason why a seal will fail. 1/ age. 2/worn pilot shaft
bearings, allowing shaft and flange to viberate. 3/Worn U=joints and/or
out of balance propeller shaft will alsoo cause the seal failure, but the
vibration should have been noticible long befor a seal failure.
and commonly 4) over 30 years the seal has worn a rough spot in the
sealing surface of the flange, which in turn will grind up any new
seal very fast.
If it is not too bad, this can be cured by machining the sealing
surface down just enough to get rid of the worn spot. It needs to be
restored to a smooth, polished finish, so find a shop that has the
right equipment. Obviously if the groove is too deep you will have to
take off too much metal and the diameter will be too small to seal
right. In this case you could get a new flange, or try building the
worn area up with welding and then resurfacing the flange ($$), or
perhaps find a "speedi-sleeve" (i think that's what they're called;
it's a very thin metal sleeve designed to fit over a dead sealing
surface to give it a new life) of the right size and use that.
This problem also happens commonly with the transmission output
flange. Actually, I think it's more common there; I suppose because
that area seems to attract more grime.
At least until recently TRF was selling the OEM leather diff pinion
seals. Much nicer than the aftermarket ones sold elsewhere. If they
have any left it's what you want.
--
John Wroclawski
jtw@lcs.mit.edu
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