How to check speedometer with out driving ( far ). A helper to count would be helpful.
Unhook cable end at speedometer head and pull out from under dash so you can see it, wrap a piece of tape around end as a flag.
Mark out 52' - 9 1/2" on a flat surface,
Roll up to the starting mark on the ground, place tape on the truck with mark to accurately align with the mark on the ground. I used a plumb bob.
Roll forward while counting turns of the cable till you travel the full 52' -9 1/2".
If it's geared right, the cable will rotate 10 times.
Repeat a couple times to verify the results.
Last edited by Joe H; 08/19/2026 11:31 AM.
