Can a 39T ring gear be used with a 10T pinion gear? I have a 39 and 40T ring gear, but the 39 is in better shape. I've never heard of a 39-10 combo. Thanks.
I don't think so. I think only the 13 tooth will work with the 39 tooth. The 10 and 11 tooth will work with the 40 tooth; at least that's what I've always been told and read.
I think ALL 39 and SOME 40 tooth ring gears are off-set (machined in on the back side) to allow for the larger diameter 13 tooth pinion. The off-set will not work well with the smaller diameter 10 tooth pinion. You could shim it back out (over? in?), however that would not be an ideal plan. (Tall stacks, or even really thick, shims can have a tendency to work loose)
The 10 tooth pinion should only be used with the flat back 40 tooth ring gear.
Drive carefully, and enjoy, W2
Thanks, thats what I need to know.