1966 c10 speedo help

[slorio]

Zcle91:
A couple of other ideas. When you have that bullet holder out, you can use a flashlight to peak inside the tranny and see the drive gear. Before I pulled out the tailshaft, I would take a look at it and run my finger across it inside the transmission to see if you see/feel any damage and whether it was plastic or steel. If you have the steel gear, it is unlikely it is damaged.

One other thought. I would measure the diameter of the driven gear that you have in your hand with a caliper. Those came in two sizes. A larger 7/8" and a smaller 13/16". They are very close in size, so a caliper is necessary to tell the difference. If someone changed the gear before you got the truck you could have a mismatch. The 13/16" is way more common and available. The larger 7/8" is only available in 22 teeth (green in color). If someone put a 13/16" gear in a truck that needed the larger 7/8" gear you would have the problems you describe.

Hope that helps.
Regards,
Steve
New Orleans