I have a ‘47 AD Chev 3100 with a 3speed floor shift. PO replaced the original engine. Not sure if the tranny is original. Discovered my speedometer wasn’t working. Attached a drill to the cable and it showed it worked properly. Took off the speedometer driven gear and probed the inside. Cannot see/feel the speedometer drive gear. Thinking it is missing…left out when the engine was replaced, I found a replacement drive gear. ( see photos). I “think” it is press fit to the Universal Joint Spacer. Cogs are compatible with the driven gear.
Since I have not opened the tranny and inspected it, I’m trying to understand the issue before I tear down.
I’m wondering if other internal parts are missing ? Looking at the ‘48-‘53 Truck Shop Manual, listed are Main Shaft Rear Bearing Snap Ring, Speedometer Drive Gear Spacer and might they also be missing? If so, where, how do I find these specific parts?
I am also confused why the Universal Joint Spacer is a smooth shaft without any splines? Is it somehow pressure fit? Seems to me it should be splined so it wouldn’t slip on the main shaft?.
I wonder if the AD model, with the 3 speed floor shift was simply an unused up ‘46 3 speed tranny that the factory installed…or didn’t want to retool for the new model?
I’m trying to understand this before I tear it down, search for parts and lose summer driving while locating/installing parts. Seems to be more of a winter project.
Many questions and little understanding, so any help you could provide would be greatly appreciated!
