[428RA4]

REAR MAIN SEAL LEAK

Well after all my efforts and replacing entire major car systems, I think I'm having a real main seal leak that is caused by vibration that increases at higher RPM's at freeway speeds. I have a brand new Ram Air V motor along with a brand new Richmond 5 speed trans. Rearend is fresh as well. The only parts that remain in question are the harmonic balancer and the drive shaft, but both are new. The balancer is an original NOS GM part and the drive shaft is supposingly balanced.

Does anyone recommend anything else to look at? Im lost for words and am about to go ape on the engine builder.

The engine has been internally balanced = crank, rods and pistons.

Balancer and drive shaft is in question, but again, any ideas on what else could cause this?

thanks

mike