REMOVAL & INSTALLATION
See Figures 1, 2 and 3
On all cars through the 200 series, the speedometer is cable driven by the transmission. The cable is connected to a drive gear in the transmission case and connects to the dashboard unit which converts the number of cable revolutions into an expression of speed and distance.
The speedometer cable is unscrewed from the rear of the speedometer (it may be necessary to remove the instrument cluster for access) and from the transmission case. When installing a new cable, seat the ends of the inner cable in both the speedometer and transmission. Cable routing is critical; at no point should the bends in the cable be any sharper than a 4 inch radius. A crimped or binding cable can cause noise, vibration and possible damage to the speedometer unit.
A tamper-proof seal is installed on all 1977 and later models, on both the speedometer connection and the transmission connection. The speedometer connection has a plastic collar which must be broken to remove the cable. The retaining bolt for the transmission side of the cable is covered by a plastic cap which must be broken in order to remove the bolt.
The 700 series does not have a mechanical cable. This series uses an electric inductive pick-up in the differential to generate speed data. The number of electrical pulses varies with the speed; the speedometer unit transforms the pulses into a readable display of speed.
An inoperative speedometer in these cars is really an electrical problem requiring the usual checking of fuses, grounds, connectors and wiring. The sensor mounted in the differential works on a critical internal clearance; it should not be removed or loosened for testing.