vetteguy75

My 75's speedo is off by 10mph (shows 60mph when actual is 70mph). The tires and wheels are stock (p255x60x15) and the HEI distributor has been replaced.

2 questions: what can cause this? and is the Odometer going to be off too?

Any help would be greatly appreciated....... :confused:

Larry B.

Someone may have changed the rear axle to another ratio or someone may have replaced the transmission drive gear, or driven gear. Also there is a chance that the speedo is just out of calibration. I any case you can replace the plastic gear in the trans (where the cable plugs in. There a a few different gears availbe to fix that. If the Odometer IS off then definatley change the gear. IF the odometer is correct then the spedo head needs attention. The odometer is a direct reading whereas the speedo is magnetically pulled by the rotating cup driven by the cable.


[Modified by silvervetteman, 9:16 PM 2/25/2003]