I bought a 55.2 248" six and Hydra-Matic a week ago from a guy that was going to rod the Burb they were original to. Separated the engine from the transmission. Sent the engine to another GMC guy in Atlanta, kept the HM to use in my daily driver '57 102. I've never separated one of these before and was surprised to find a "seal" in a groove in the transmission side of the flywheel, just inside the gasket with all the holes in it that goes between the torus cover and the flywheel. The seal was so brittle that it was easily broken by hand. I've looked though all my Hydra-Matic parts books and can find no reference to this seal. Same lack of info in the GMC Master Parts Book. I did find reference to it in "GMC Trucks Hydra-Matic Transmission Operation and Maintenance" Part I, page 69. See attachment for both a picture and the instructions that tell you to remove it after removing the transmission. Instructions never tell you to put it back in. Anyone have a part number for this beast? Need it for the V8 flywheel, which is shared with '55 and some '56 Pontiacs.
Hopefully, I'm da man! Check out this link and scroll down to the transmission parts section on the left. www.pontiacparts.net/Mechanical/default.htm Happy hunting!
Got this figured out. The V8 torus to flywheel connection was sealed by a paper gasket that has 32 holes in it for bolts and alignment pins. The six cylinder torus uses an o-ring of sorts that fits into a groove machined into the flywheel and torus.
Jeez Ken, How do you DOOOOO that??? Always Johnny on the spot with the internet sites that we need. You are truly amazing. When I first read Bill's thread I thought "good luck finding THAT part", but it seems that you have indeed come through again. Here's hoping that Bill's slip and slide gets back together soon. Andy
