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+--- Thread: Rear main bearing oil seal (/showthread.php?tid=9759)
Rear main bearing oil seal - Dave Mann - 13-12-2024
I fitted a lip seal to the rear main since when it leaks like a colander, the flywheel boss runs true and is as smooth as a baby's bum and yes the oil thrower is fitted, so what is wrong?
RE: Rear main bearing oil seal - Alan - 13-12-2024
Is the flywheel boss undersized?
RE: Rear main bearing oil seal - Steve Jones - 13-12-2024
Happened to me once and the answer was as Alan suggests. From then, always fitted the boss with an appropriate speedi-sleeve and never had another problem.
Steve
RE: Rear main bearing oil seal - Dave Mann - 13-12-2024
No it's within the size range for the seal
RE: Rear main bearing oil seal - Peter Naulls - 13-12-2024
Both of mine leak copiously too. Looking forward to the solution!
RE: Rear main bearing oil seal - Tony Press - 13-12-2024
Silly question- seal is the right way around ?
RE: Rear main bearing oil seal - dickie65 - 13-12-2024
Likely that the flywheel and seal plate are not concentric.
Also check the drain hole in the housing is in the correct place and not blocked with sealant.
RE: Rear main bearing oil seal - Brice - 14-12-2024
What possibly helped me, was to ensure that the crankcase was able to breathe (pipe connected to the oil filler tube that leads away to the side of the car) this seemed to take the pressure away from the modern lip seal/speedy sleeve arrangement (no oil thrower) and reduce oil leaking from the bell housing drain hole.
RE: Rear main bearing oil seal - Dave Mann - 14-12-2024
I checked for run out of the flywheel boss, less than 0.001", getting in to check concentricity of boss and seal is somewhat difficult. The engine has a crankcase vent to the air intake giving a depression of 3/4" water gauge.
RE: Rear main bearing oil seal - Steve Bryant - 14-12-2024
Since crankcase ventilation of engines such as ours are so important, I modified my side cover with a chamber and pipe to road draft the fumes under the rear of the bell housing. It has yet to be tested but I'm confident it should work well.
Stephen