I have a 1977 F-100 manual transmission truck.
The speedometer driven gear in the transfer case spins freely on
the shaft so the speedometer itself doesn't move.
Can anyone give me a rough estimate of the cost to fix this problem.
I don't know how the gear was pinned to the shaft. Thanks for any help.

 

Determine which gear is bad. If it is the driven gear figure out if the gear or the cable is bad and replace the part.

 

Apparently I wasn't clear. the gear attached to the speedometer cable is OK.
The gear inside the transfer case that drives the gear on the cable is not attached to its shaft for some reason. I want to know about how much it would cost to reattach the gear to its shaft, since as best I can tell the transfer case would have to be removed from the truck and partially disassembled.

 

I had this happen, but it was inside the transfer case on my highboy.

Removed the rear yoke, bearing/seal retainer, and the gear was right there.

Shouldn't be too hard to change it, what tranny is it?

 

3 speed manual

 

Give me the tranny code off the door sticker if you have it, just to make sure, but I checked my Motor's truck repair manual for '79 (not the best).

It looks like you could remove the extension housing (I'm assuming the driveshaft slips into the end of the tranny?), and get to the speedo gear.

I notice that the speedo gear goes on over a "lock ball" - which is a ball bearing with a coil spring, and then a snap ring goes on the shaft to hold the gear in place. The ball bearing and spring are probably rolling around the extension housing, or maybe that's the problem, the coil spring broke or something so the gear is not locked onto the shaft anymore. Either way, you have a problem with that speedo gear, and you have to get the extension housing off.

GUYS?!!?!? Anyone else with experience taking off the extension housing on a Ford 3-speed?