Smiths speedometer off

[KirkV]

So here's the deal,only once I get above 50 mph does the speedo read off and it reads higher than what I am actually going. How can it be on at the lower speeds but off on the higher?

[strictlypersonl]

If what you say is true, either replace the speedo or see whether Nisonger can repair it. You can't fix a non-linear response externally.

[spdbrake]

Since ratios can be expressed as percent or fractions, the faster you go the larger the error you'll see.

Tire dia chosen is usually the 1st factor people experience in this issue.

I had plenty of issues on 4wd truck and large tires over the years. In some cases I lived with the error once I knew whats it was and in others I changed pick-off gears.

This article may help explain the factors.

https://www.thrillist.com/cars/your-...-japanese-cars

Speedo error calculator

Newer VDO, Autometer, Speedhut speedos can usually be custom recalb on a specific measured distance driven by the consumer.