RV Roamer said:If push comes to shove, you can determine it manually as follows:
Place transmission in neutral and elevate one tire (make sure vehicle won't roll!). Mark tire and driveshaft, turn tire two complete revolutions while counting number of turns of the driveshaft. This is your Actual Gear Ratio. i.e. 3 turns + 3.00 ratio, 4.1 turns = 4.1 ratio, etc.