Speedometer Drive Replacement

[sofia72]

Replacing the Speedometer Drive

I just replaced the speedometer drive in my 1972 Fiat 124 Spider, without removing the transmission from the car. Here is how I did it:
1. Raise the car so all 4 wheels are off the ground. You need to raise the rear wheels, because you’ll need to turn the driveshaft.
2. Disconnect the speedometer cable from the drive.
3. Remove the 3 bolts, on the transmission side, from the rubber doughnut, turning the driveshaft to provide access to the bolts.
4. Push the driveshaft back, freeing it from the Tx.
5. With the Tx supported with a floor jack, remove the crossmember support to chassis nuts and lower the Tx. Remove the soft support bracket from the Tx, to get it out of the way.
6. Now you have to “really” push the Tx to the right and down at the same time in order to get enough clearance between the floor and the Tx to extract the drive. I used a 1-foot long 2x4 as a lever and inserted it about 4 inches up between the tunnel and the Tx and used a tie down strap attached to the chassis to pull the 2x4 to the left, pushing the Tx over to the right and down at the same time. (Unfortunately, I’m not able to attach a pic.) Just when you don’t think you can get it out, you tighten the strap a bit more, and “wallah” it slides out. That’s a good day!

Also, I had to change the speedometer cable and housing, because the housing was badly pinched, which was a pain removing the old one and then fishing the new one back through the car. If you only have the replace the cable, it’s best to just buy the cable and then fish it through the housing at the speedometer gauge end.