I have a 235 6 cylinder engine in a 55 chevy . The rear main seal started leaking so I first replaced the lower half, the leak got worse. I then replaced both the upper and lower half with a new seal,no improvement. I am using the neoprene type seal. I installed the seal per the instructions and I did not use any sealers and I am keeping the ends of the seal dry before assembly. I am facing the seal the proper way. I am lubing the seal with motor oil before assembly. The local auto parts store only lists 2 types of seals, the one I am using and the old rope type. Is there something I am missing? Is there another seal available?
I called Fel Pro and the suggestions they had was to stagger the seal slighty and check the bearing clearances. I checked the bearing inserts while I had it apart and they look fine, I used plastigauge when I built it and the bearings were at factory specs. The block was line bored and the mains on the crank were turned .030 during the rebuild. Is .030 enough to cause problems with the seal? The seal surface on the crank is fine. It has about 20,000 miles on it since a complete rebuild. Should I be using some type of sealer in the main cap grooves? Does anyone know of a way to fix the leak? The current leak will cover about 1/2 of the surface of a flat drip pan in one week. The engine runs fine but I want to end this leak. It leaks when it is running and after it stops it will drip about 1 drop per 30 seconds out of the bearing cap for about 3 minutes.
I have heard that 55 was the first year that the neoprene type seal was available and that the caps didn't necessarily fit the new seal that well. If that is the case, will silicone fix the fit?
