VCI logo Archive Index | Current Issue
Some Notes on Reviving Speedometers
Shaun Redmond

Although I have been working on Volvos for years (mostly 140s and 240s), I recently fulfilled one of my dreams and purchased an orange P1800 ES. I spent a week in April driving it back from Washington State to my home in Guelph, Ontario. I spent two days before the trek getting the car tuned up and taking care of any safety issues. The speedo cable in the car was broken; this forced me to determine speed by RPM instead of MPH.

I popped the speedo out of the dash once I got home and attached the speedo cable to test it out. I twisted the cable and it didn't want to budge. I removed the cable from the back of the speedo and examined the "connector" that the square end of the cable fits into. It appeared to be seized.

I found that a #8 square drive (known as "Robertson," here in Canada) screwdriver fits perfectly into the connector. I placed the speedo face down and applied a liberal amount of a special teflon penetrating oil (Finish Line Bicycle Lubricant) to the bearing surface of the connector and let it sit for twenty-four hours. I then inserted the square drive screwdriver end into the connector and carefully worked it back and forth to free it. I continued this for about five minutes, being careful to use a Q-tip to mop up any rusty gunk that came out and replenish it with fresh teflon lube.

I continued to work it free until I felt it was time to test it at "road speed." I placed the square drive bit in my drill and set it to reverse direction. I varied the RPM between 200 and 700 to make sure it would handle normal operations on the road.

I think if people with bouncy speedometers have a good speedo gear and a cable that works, they may want to lubricate the outer bearing of the connector on the back of the speedometer with teflon lubricant and flow some down the inside of the seedometer cable to keep it rotating smoothly. Flowing the teflon lubricant into the speedo cable is best done by holding the upper end vertical and squirting the teflon lube into the housing at the end of the cable. Gravity should feed it down the length of the cable. When the "carrier" part of the lubricant evaporates, the teflon will adhere to the cable and shroud, making it operate with much less friction.

Back to the Top