), and count the revolutions of the propshaft. Can do it the other way if you like (turn prop shaft, count rear wheel revolutions). You will need some precision to ensure the result is accurate, which means a couple of people, and a tape measure to measure circumference of wheel and get accurate measurement of part revolutions.If it is out of the car, yes just count the teeth and plug them into your calculator (big number divided by small number) if metal arithmetic is not your strength
)
