Before installing a speedometer cable, it is wise to make sure that the speedometer is not locked up and that the speedometer gear is working. The speedometer gear is held into the tail housing by a small flat piece of steel with a 3/8 bolt through it. The flat piece fits into a recess in the speedometer gear housing to hold it in place. Remove the bolt and flat piece to pull the gear out. Check the gear for any wear or missing teeth. Rotate the gear by hand if possible. If it will not rotate, the cable or the speedometer is locked up.
Remove the cable from the gear by unscrewing the cap and separating the two. Look at the end of the cable that was in the gear and see if it is still square and not broken off. If the gear did turn, spin the gear and have someone help by watching the speedometer. It should jump when the gear is spun by hand. If it does then the gear in the tail housing is bad.
Remove the cable from the gear if it is not already. Remove all clamps holding the cable to the body under the car. Inside the car, the dash cover face that covers the front of the instrument panel must be removed. Remove the screws in the cover. Use a common screwdriver to pry the snaps on the cover loose from the dash. Disconnect all electrical connectors and remove the cover. Remove the screws holding the speedometer pod to the dash.
Raise the hood of the car and locate where the speedometer cable runs through the firewall close to the steering column. The cable will have a rubber grommet that seals the hole in the firewall where it enters. The grommet does not slide on the cable, so use a long screwdriver or similar device and push the grommet through the firewall toward the inside of the car. Go inside the car and the cable can be seen under the dash. Use a wire cutter to cut the grommet off the cable. Now the cable is loose and will come out with the speedometer. Carefully and slowly pull the speedometer out enough to get a hand behind it. Undo the speedometer cable. It may be necessary to disconnect the electrical connector in order to get a hand in the back to the speedometer cable.
Most all cables have a squeeze-type lock on the back of the speedometer. Some have a simple screw cap like on the gear. To get the squeeze type off, pinch the top and bottom of the clamp and pull the cable out. The cable will not pull out of the firewall inward because the gear-side screw cap is larger than the hole in the firewall, so pull it out from under the hood.
To install the cable insert it through the firewall from the engine side first. Go inside and pull it in as far as it goes until it contacts the grommet. Use your fingers to push the grommet into the hole and seat it properly. Go inside the car and insert the speedometer cable into the speedometer. If it does not want to go in easy pull it back a little and turn the cable with your fingers. Try it again until the square end lines up and it slides in.
Push the cable all the way in until the squeeze type retainer clicks into place or if it is a screw type simply screw it on. Reinstall the pod and dash cover. Under the car, install the cable into the brackets that were previously holding it. Install the end of the cable into the speedometer gear the same as in the car. Rotate the cable end until it slides in. Tighten the screw cap.
