Hi Perry
Can you be more specific about which bearings. I've been playing with these for forty years, and they are very tolerate of play that would kill a modern transmission. But they are also vocal about the amount of accumulated play inside.
The main and secondary ball bearing are the most critical also the easiest to get and replace. The needle bearings seem to most likely to get unnervingly noisy as they will rumble, chatter and vibrate as the clearances get to large.
I've posted some photos and information I've experienced driving and working on these transmissions over the years:
https://www.canadianmilitarypattern....ansmission.htm
https://www.canadianmilitarypattern....nchevrolet.pdf Manual Section
http://www.canadianmilitarypattern.c...ansmission.htm
Unfortunately some of the sources for parts I've mentioned and used over the years are no longer in business. I got lucky the last time I had a transmission problem, broken tooth, and found a complete NOS transmission, also found the repacement gear need. Cleaned and installed the NOS transmission which still after several thousand miles shift much stiffer than the other 3 transmissions. Rebuilt the other transmission filled with gear lube and sealed it up and put it on the shelf as a spare. Hope it will guarantee I'll never have transmission problem with any of the trucks.
Take pictures as you disassemble and share the photos of what you find.
All three of my CMPs share the same transmission, each of them sounds different, shifts differently and has different vibration pattern as felt through the gear shift.
Cheers Phil