Recently I was driving 50 miles on a washboard dirt road (saline valley) after about 30 miles of all the bumpiness my speedometer and odometer stopped working. I’ve checked the fuses and they are all OK. I have no idea what to do next. I’d also like to fix the rpm gauge which has never worked. Can anybody suggest how I should trouble shoot getting these gauges working again.

Thanks

Maybe your speedometer cable broke or fell out of the trasnmission case ? The cable also obviously drives to tachometer.