No numbers or ring gear

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Nov 15, 2008
Tampa, FL
Trying to determine if my front diff and rear diff are the same ratio... no looking good. I have coarse spine up at front pinion flange and turning the wheel gives me a 4.1 ratio at driveshaft.

On the rear, I tried the rotating tire trick but brakes kept sticking and preventing freewheel.

I pulled the diff cover plate and there are no numbers on my ring gear, looked at posts to assure and I'm looking at the right spot. Pushed cruiser up and back 10 feet to assure I'm not missing a section. Has Japanese letters on the side of the gear. I counted the pinion and it has 10 gears. From what I've read 10 gears on the pinion is 3.7... end of story right? There is no way I can have 4.1 on the rear if I have a 10 gear pinion?

Thanks ahead, CD:beer:
I am not familiar with how many teeth are on each pinion but, the way I have always done it is count the number of the teeth on both the ring gear and the pinion and divide the the ring gear number by the pinion number to get the gear ratio.
Thanks ended up doing that... Kurt at Cruiser Outfitters said there were several aftermarket versions that had 10 tooth pinions. Bad part was its 3.7. So now I'm looking at a total front axle/hub/ring/pinion rebuild. Probably the only part of a vehicle I haven't torn into before, but you got to learn somehow.

Don't know if anyone makes such a set, but 10 teeth on the pinion and 41 on the ring would net 4.1. If you had different ratios front to rear, it must of behaved really badly in four wheel drive!! John
i believe they are 37.10 3.70 or 37. 11 4.11 mutiply the first no,by the second one to get the ratio.
Kurt at CO really schooled me on this. Although 37 x 10(3.70) and 37x11(4.1) are the most common ring/pinion and factory setup, there are several after market combinations that can have 10 or 11 pinion gear with different ratios. He explained that you really have to count both to be totally sure.

I do have 4.1 up front and 3.7 in the back, which is probably why PO had the front driveshaft off when I bought it...

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