Removal. Gearbox B5 and iB5
Remove the negative terminal from the battery. Loosen the lock nut and remove the speedometer drive cable from the drive pinion or vehicle speed sensor on top of the transmission. If there is a vehicle speed sensor, you will need to use two wrenches, one to secure the nut to the sensor and one to loosen the lock nut on the speedometer drive cable (see Fig. 7A.14).
Disconnect the electrical connector from the vehicle speed sensor, then unscrew the sensor from the top of the speedometer drive gear. Remove the speedometer drive gear.
When removing the speedometer drive gear, be careful because the drive gear bearing is not secured to it and can be easily removed (see Fig. 7A.15).
Using a small screwdriver, remove the O-ring from the bearing groove. Clean the speedometer drive gear and bearing, as well as the socket in the transmission housing for the gear.
Removal. Gearbox MTX-75
The speedometer drive gear can be accessed from the top of the engine compartment or from underneath, with the front of the car raised and secured on stands. Unscrew the nut and disconnect the speedometer drive cable from the vehicle speed sensor on the gearbox. To do this, use two wrenches, place one on the sensor and use the other to unscrew the speedometer cable mounting nut.
Disconnect the electrical connector from the vehicle speed sensor, then unscrew the sensor from the top of the speedometer drive gear. Remove the pinion retaining roll pinion from the transmission case. Remove the speedometer drive gear with bearing from the transmission case. Using a small screwdriver, remove the O-ring from the bearing groove. Clean the speedometer drive gear and bearing, as well as the socket in the transmission case for the gear.
Installation. All models
Installation is performed in the reverse order of removal. When installing, lubricate the O-ring with a thin layer of engine oil and hammer in the cylindrical pin securing the speedometer drive gear (see Fig. 7A.16).
