Hello, I was wondering how I would find the gear ratio of the rear end? I have a 2000 4X4 4.3 liter Chevy Blazer. We believe the gears are shot because we jacked it up, spun the tire once, and didn't even count a full revolution of the drive shaft. So that didn't help us. We also looked in the glove box and found a series of numbers, which the internet said to look for one starting with the letter "g". We found one labeled "GU6" and looked it up and said it was a gear ratio of 3:42. Does that sound right? is there any other way of finding it?

Thank you for looking,

 

glove box is the easiest way, sounds right to me

 

Another way to check is to jack up one side of the car and have the truck in neutral and turn the driveshaft one revolution and count how many times the tire spun around that should be close to the number gear ratio you have. For example if you have a 3.42 then the tire went around and 3 full turns and almost a half of a turn

 

reverse that and you would be right.... 3.42 revolutions of the shaft would be one tire revolution

 

Remember that the spyder gears are invoked with one wheel off the ground. So it would be 3 and a half turns of the driveshaft would result in 2 turns of the tire!