I'm not a transmission expert but if its quiet in 4th I'd expect either a bearing or a broken gear on the counter shaft.

It doesn't really matter because your options are the same regardless of what's wrong. Either you rebuild it or replace it. I know a guy who rebuilt his and said it was easy. I have a spare so I'd just replace mine if it were giving trouble.


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...