Tools You'll Need:
* New speedometer cable: Make sure you get the correct one for your specific model.
* Socket set: Various sizes will likely be needed.
* Screwdrivers: Phillips and flathead.
* Pliers: Needle-nose pliers are helpful for some connections.
* Wrench: Possibly a box-end or open-end wrench.
* Jack and jack stands (highly recommended): For easier access to the transmission.
* Wheel chocks: For safety.
* Shop rags or paper towels: To keep things clean.
* Penetrating oil (like PB Blaster): To help loosen rusted or seized connections.
Procedure:
1. Safety First: Engage the parking brake firmly. Use jack stands to safely lift the truck, and chock the wheels. Never work under a vehicle supported only by a jack.
2. Locate the Speedometer Cable: The cable connects to the transmission at one end and the speedometer in the instrument cluster at the other. Trace the cable from the instrument cluster to find its connection point at the transmission. This is usually underneath the vehicle, near the transmission.
3. Disconnect the Cable at the Transmission: This is the more challenging part. You'll need to access the connection point at the transmission. Often, there is a retaining clip or a nut securing the cable. Apply penetrating oil if needed and allow time for it to soak in. Use the appropriate wrench or pliers to carefully remove the cable from the transmission. Take a picture before disconnecting to help you remember how it was assembled.
4. Disconnect the Cable at the Instrument Cluster: This is generally easier. Access the speedometer cable from inside the vehicle by removing the instrument cluster bezel (the plastic trim around the gauges). There will be a connector at the back of the speedometer. Carefully disconnect this connector. Some vehicles may require disconnecting the whole instrument cluster. Consult a repair manual if needed.
5. Route the New Cable: Carefully feed the new cable into place, following the path of the old cable. This may require some maneuvering. Make sure it is not kinked or pinched anywhere along its route.
6. Connect the New Cable at the Transmission: Connect the new cable to the transmission, ensuring it is securely fastened. Again, refer to your picture or repair manual if needed.
7. Connect the New Cable at the Instrument Cluster: Connect the new cable to the speedometer at the instrument cluster. Reassemble the instrument cluster bezel.
8. Test the Speedometer: Lower the vehicle, and test the speedometer by driving the truck. Ensure it works correctly. If it doesn't, double-check all connections.
Important Considerations:
* Repair Manual: A repair manual specific to your 1986 Nissan pickup will be invaluable. It will provide detailed diagrams and instructions.
* Year and Model Variations: There might be slight variations in the procedure depending on the exact year and model of your truck. Always double-check your specific vehicle's components.
* Stubborn Connections: If connections are particularly stubborn, don't force them. Excessive force can cause damage. Apply more penetrating oil and let it sit.
* Cable Length: Make absolutely certain the replacement cable is the correct length. Too short or too long will cause problems.
This guide provides general instructions. Always consult a repair manual for your specific vehicle model before starting any repair work. If you're not comfortable performing this repair yourself, it's best to take it to a qualified mechanic.
