So I wanted to freshen the SM420 that came from my 1953 Chevy 1300 (Canadian version of a US 3100). It does run and shifted reasonably if you didn't try to shift too fast. 3rd gear always had a howl to it which was the main issue I was hoping to address. There wasn't really any issue with popping out of gear or anything like that.
I ordered the Novak rebuild kit and started the tear down and inspection process. As you can see from the pictures (hopefully they work), the gear pressure faces look pretty nice but any of the synchro teeth on the gears … not sure if that's the right terminology… look pretty badly worn. First and reverse gears are badly worn on the corners just from being unsynchronized and likely abused over the years. My uncle told me about how my grandpa used this truck for crop spray in the 70s so it probably makes sense it's a little rough. Oddly, the brass synchro rings look to be in better shape than the steel bits?
Being that it (seemingly miraculously) shifted OK for a 70yr old truck, what is the right course of action here?
1) Don't worry about it. Freshen it up with the Novak kit and run it. Hopefully quiets down 3rd gear.
2) Source the replacement gears that are needed. Are there are I should be less/more concerned with? Seems like the parts cost could add up real quick.
3) Look for another SM420 that is hopefully in better shape.
Let me know what you figure. Thanks for your help!
