Re: Speedometer not accurate...
I removed the driven gear. It's 16R and is light yellow. I believe 16 is the correct teeth based on the formula. I've heard that the drive gear is 7 and is specific to the C4 transmission. Is it possible that is not actually the one being used? If so, could that be the reason for the issue, can it be removed and where is it located? What are other possible sources of the speedometer problem?
Differential Gear Ratio= 2.83
Rear Tire Diameter (Inches)= 26.11
Speedometer Revolutions/mile = 773
Drive Gear Teeth Number = 7
1966 MUSTANG Convertible (L6, Sprint 200, 3.3L, Original owner) (C-4 Auto rebuilt trans, power steering, manual drum brakes: F&R 9") (Single exhaust, 7.25" rear, 2.83 ratio, P205/75R14 tires) (Candyapple Red exterior, Red interior, White power top).