My '53 Chevy has this strong thumping vibration as I get into the 30-40mph in 4th gear.
I can't seem to get the truck to go over 42mph in 4th gear.
It gets worse when I let up on gas.
Is this a transmission problem? I have a floor shift 4 speed. The differential looks great. I re-did the drive shafts/universals.
Also - who made these 4 speeds?
This is a 53' truck with a 1961 235 - could it be a mounting problem with the older trans on newer 6?
Ron
