MTFCA Forum

I have a 10 tooth pinion that is marked 10-42, will that work on a 40 tooth ring gear? It looks just slightly different. Thanks for any help that I can get. Dennis

It will probably work but would be noisy.

Art Mirtes

Was the new pinion designed to run with Ford gears? NO
Will it? Maybe.
Will it create new fit issues with gear teeth clearance? Likely.
Will it be noisey? Maybe.
Is the metallurgy good to where a tooth wont break off? Maybe.

Back in the day, changing to a 10T pinion meant only pulling the D.S. Doing that with this gear would certainly be a problem.

You can roll the pinion on the intended ring gear. If it seems to mesh without clicking, it might work.

All the risk, hassle & potential wasted time worth it?
NO, not when a NOS ford gear is readily available here @ a fair price. NOS!!!
(I bumped it up just for you)

Thank you John, I called and am getting the one that you pointed out. Thanks again. Dennis

Wise decision. & you cant go wrong with genuine NOS.

No one makes a "new" 42 tooth ring gear. Good luck finding a good used one.