I dont how the weather is in Utah...but its to damn hot here to do all that when you can do it in 3 minutes on the puter! Work smarter not harder!Gear ratio is simply the number of rotations of the driveshaft divided by the number of rotations of the axleshaft. I would simply jack the back end up, rotate the wheels through one rotation while counting the number of rotations of the driveshaft.