How to find out diff. info?

[cwatt]

Hey all,

I ran my vin through an online decoder and it comes up saying it has the Canadian package which I think means it's an LSD. How do I confirm this (it's off the vehicle already), and how do I find out the gearing ratio?


many thanks all,
- Colin

[jalopi]

Morning Colin,

I'm guessing the tag is missing off of your diff? If so, since it's already off the car, try grabbing one of the axle flanges and spinning it forwards. If the other axle flange spins in the same direction you've (most likely) got an LSD.

The best way to calculate the gear ratio is to pop the cover off, count the teeth on the ring gear and divide by the number of teeth on the pinion gear. However, a simpler and easier (and nowhere near as accurate) method is to count how many times the axle flanges rotate per revolution of the driveshaft flange.

[ttrousdell]

Is the tag missing? If not did it come with a tag similar to this?

[jlevie]

If the tag is missing, checking to see if there is lockup between the output flanges will tell if it is an limited slip. The torque required to break that lockup will tell the condition of the clutches. Counting the turns of the input flange for one revolution of an output flange will tell the ratio.

[cwatt]

HI everyone,

Thanks for the responses. I'm unfortunately not going to be much help.. haha. The tag is missing and I accidentally sold the output shafts when I sold the rest of the rear suspension. I'm hoping to get them back from the person I sold them to, but I don't have an accurate way to measure rotations manually.

There are some raised lettering on the diff itself. Any chance they mean something?

[vpilarrt]

You don't have to be that accurate in counting revolutions. Most of the diffs are about 10% apart in ratios. LSDs have a "S" (about 3" tall) painted on the top.