I have always heard of how you mark the tire and driveshaft, then see how many turns of the driveshaft it takes to turn the tire once. I tried this for I think the third time and it hasnt worked out to well. This time I spun the driveshaft and my 14 Bolt axle turned the tire once after only 2 turns of the driveshaft. I know my axle is not 2:1 gears. So what gives?? And I did the test where you turn one wheel forward and the other wheel went backwards so a locker or two is definately on the list.