Posted by Fred Coldwell on August 28, 2000 at 11:15:38:
In Reply to: Axel Ratios - How to tell posted by Drew on August 28, 2000 at 00:17:36:
Here is another method to determine the axle ratio in an axle with an open differential (no locker) without moving the truck. This works especially great on immobile trucks.
Mark the driveshaft, jack one tire slightly off the ground so it spins freely. Spin it around twice (two complete revolutions, or 720 degrees) and count the number of revolutions of the driveshaft. Just under 5 driveshaft revolutions equals 4.89 ratio, way over 5 but under 6 driveshaft revolutions shows a 5.83 gear set. Two tire revolutions are needed to find the axle ratio when the opposite tire remains on the ground because the gears in the open differential turn the drive shaft at half-speed.