I have been told you can get a good idea of what gearing is in the rear of a car by turning the rear tires and looking at the drive shaft. As I have heard you are suppose to count the turns on each to get an idea of gearing. If the tire is turned 1 rotations the drive shaft turns 3 then it is a low 3's rear and if it turns 4 it is something near a 4.11. Is that correct? I am going to look at a rear end and wanted to be sure how to check the gearing.
That works fine for posi, but won't work for one-legger unless you spin both tires together.
If you don't have posi, let one tire sit on the ground (jack up the other) and spin the airborne wheel twice - not once - while counting driveshaft revs. Driveshaft revs per two trunes of a single wheel will be close to the rear end ratio.
Without air should be 3.08. If you decide to pop the cover, the number of pinon & ring gear teeth is stamped onto the ring gear, which should save your fingers from counting.
Thanks, Dr. D and Quenton. I assumed a 3:08 since I am getting approx. 17 MPG city and 20 MPG highway. next time I change the fluid, last done by the shop on Feb 2010, I will confirm it for myself.
Just pull the cover, count the pinion gear teeth and the ring gear teeth and divide. Fluid probably needs changing anyway.
With doc on that one! $25 in lube, gasket and additive (if needed) plus some brake kleen to get the gunk out. Then you can see your numerical ratio stamped on the ring gear.
Originally Posted By 69 Bird
Thanks, Dr. D and Quenton. I assumed a 3:08 since I am getting approx. 17 MPG city and 20 MPG highway. next time I change the fluid, last done by the shop on Feb 2010, I will confirm it for myself.
Good thing I read the last posts....all dressed up and nowhere to go.
Si Vis Pacem Parabellum
1967 Starlight black PMD Engineering 400 Auto 1968 Alpine Blue 400 4 speed 1968 Verdoro Green 400 HO 4 speed 2013 1LE 2SS/RS Inferno Orange Camaro.
If you don't want to open the differential right now, the axle code is stamped on the left axle tube on the back about 6 inches to the left of the differential. Take a wire brush when you look cause it rusts over. Look up the code an you'll know what ratio that rear had from the factory.
If you don't want to open the differential right now, the axle code is stamped on the left axle tube on the back about 6 inches to the left of the differential. Take a wire brush when you look cause it rusts over. Look up the code an you'll know what ratio that rear had from the factory.
