I have a 71 F100 that had the column shift tranny swapped for a 4 on the floor. The speedometer didn't work when I got the truck. When I pulled the speedo cable the gear was a little stripped. I ordered a new gear and presto, It still does not work. When I manually twist the drive shaft inside the cable the speedometer moves so the cable is good. How do I figure out what drive gear I need for an unknown transmission? I am new to fixing basket cases that are not stock so please be gentle.

 

Limey, What side of the transmisson does the cable go into?
Kenny Nunez

 

It goes in the driver's side of the transmission.

 

Lime, Is the transmisson a "toploader" Ford or an earlier style "sideloader",or is it a heavy duty truck transmisson. look inside where the cable goes in and count the teeth on the drive gear. This may help to identify what you have. Also,try to determine what 1st gear ratio the transmisson is. Raise the rear wheels and chalk mark the driveshaft and tail shaft housing , remove the coil wire and have someone turn the engine by hand and count the turns to make the driveshaft make 1 turn. The "number dummy" on this site is a great help on these type of problems. Kenny Nunez