Nylon trans gear

[gasman826]

I changed the Raunch Wagon from FOM to AOD.  Other than tooth count for rear gear ratio, no change was needed.  I changed the Custom from OEM three speed manual to C6 to TKO600 with no speedometer cable change.  I have a drawer full of speedo gears with different tooth count than will fit almost all left side drive speedometer applications.  Most of these gears will interchange right up to the end of mechanical speedometers.  There are different gears for right side speedo drives.

If Bob's Speedometer rebuild the speedometer, I doubt the speedometer is the problem.  I would test the speedometer and cable by disconnecting the speedo cable at the transmission.  The gear has a bearing support on the end which is perfect for chucking into a cordless drill.  Lock the drill trigger and go look at the speedometer.  If speedo is not working, reverse the drill.  If speedo is working, your problem is in the transmission.  For some reason, C4s have different tooth counts on the driving gear (output shaft).  I've seen a couple of times that due to mix and matching C4 parts would have too much runout in the tailhousing area so the speedo gear had poor engagement.

The transmission end of the speedo cable should be the FORD style like in the previous post PIC.