Quote from Grand73Am:
Okay, an easy way to check the ratio, without opening it, is to put a floor jack under the rear end and jack both rear wheels off the ground. Block the front wheels so it doesn't move.
First you have to determine if the rear is a posi or not. With the car in neutral, turn one wheel forward. If the other wheel turns forward you have a posi. If the other wheel turns backwards, it's not a posi.
Put a mark or piece of tape on the driveshaft and also on one tire.
If you have a posi, with both wheels off the ground, turn the tire ONCE, counting the revolutions of the driveshaft. The number of revolutions is your ratio. So, for example if the driveshaft turns about 3 3/4 turns, it's a 3.73.
If you don't have a posi, jack only one wheel up off the ground, leaving the other one on the ground. Turn your tire TWICE, counting the driveshaft revolutions, and the number of driveshaft revolutions is your ratio.
