You would have to contact Recreative Industries for the rebuild kit. I assume you are talking about the output bearings on the T-20. I'd be very surprised if you where able to get them locally. RI has the bearing race specially ground for the application. Some members use grey gasket sealer instead of the paper gaskets between the case halves. As the T-20 is opened up unless the bands look new I'd just send them out to transmission crafters and have them re-lined. Not too pricey for piece of mind.
"Don't worry my Dad's a TV repairman, he has an excellent set of tools..I can fix It"