count the teeth on the ring, count the teeth on the pinion....divide.

I didn't rebuild mine, but mine also has one hellofva preload, and it pretty much always locked :rofl:

you can buy all the parts from mazdaperformance if you do....

most of them were 4.10

I did the install last weekend. Man, that things heavy. It's a 4.1. So I keep the same ratio.

Well, you could have opened it up, used dial calipers and measured the thickness of the friction plates and discs. You would have known how worn out it was. I did this on one that had about 120k miles on it, found it had almost NO wear on it. I didn't add any shims to up the preload, didn't need it to wear out any quicker and it locks up just fine as it is. BTW, I only paid $75 for mine!

Didn't measure the wear but it grips up great. Paid $110 shipped across the country.

make looked good so it was ok with me, didn't want to open it up. So once installed I tested the preload. One tire on the ground, turning the hub with a troque wrench it took 190lbs. to get it to slip.