Counting Gears?/ How to find gear ratio?

[Link85x]

How do i find the gear ratio of a rearend that is not on a car? Do i take the housing of the rear and count the teeth around the gear, or something along those lines?

[Pewter'01SS]

Count the number of teeth on the pinion gear and on the ring gear. Divide the number on the pinion into the number in the ring.

[Link85x]

Thanks.

[89IROC&RS]

or if you can read the casting number on the axle you can find out that way. but counting can work too

[Link85x]

Where at on the axle? That way, i find the number tonight, post tomorrow. I won't have time to count until this weekend, but i want to find out sooner than later.

[89IROC&RS]

well its not like a clear 3.23 or anything, but the drive side axle tube on the side pointing to the front of the car, should have like a ten digit code on it, it might need a wire brush to take off surface grime to read it, but be gentle because the numbers may be hard to read.

[89IROC&RS]

also, do you have access to the car it came out of/???? where did you get the gears from?

[Link85x]

No access to the car. If had the vin #, you'd be able to tell, right?

[89IROC&RS]

well, the dealership could, if you can get the VIN, you can go to the dealership, they can bring up the SPID lable for that car, which would include the rear end code.