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Daves-corral · 04-15-2002, 09:22 PM

I have a 1966 Mustang, that has a speedometer that is reading about 25% low. For example when a drive a known distance, in this case 80 miles, the odometer indicates 60 miles, and the speedometer is also indicating low. I have replaced the plastic gear with the one the factory calls for, with the same results. It has 16 teeth. It would appear that I need one with LESS teeth, but I have not been able to find any with less teeth. I have found units with up to 20 teeth, but this would make the situation worse. Engine, 289; transmission C-4 (not sure of year), diff 2.80/1 gears. I have factory styled steel 14 inch wheels on the car, with radials very close to the original tire size.

Any ideas would be greatly appreciated.

04-15-2002, 09:22 PM	#1
Daves-corral Registered Member Join Date: Apr 2002 Location: Allentown, PA Posts: 2	speedometer/odometer reading low I have a 1966 Mustang, that has a speedometer that is reading about 25% low. For example when a drive a known distance, in this case 80 miles, the odometer indicates 60 miles, and the speedometer is also indicating low. I have replaced the plastic gear with the one the factory calls for, with the same results. It has 16 teeth. It would appear that I need one with LESS teeth, but I have not been able to find any with less teeth. I have found units with up to 20 teeth, but this would make the situation worse. Engine, 289; transmission C-4 (not sure of year), diff 2.80/1 gears. I have factory styled steel 14 inch wheels on the car, with radials very close to the original tire size. Any ideas would be greatly appreciated.