17 tooth speedometer gear in a 1940

[Dan Hay]

So I guess a 17 housing is like hens teeth? Should I round up a more common 18 housing and gear and be done with it?

[JM 35 Sedan]

Originally Posted by Dan Hay

So I guess a 17 housing is like hens teeth? Should I round up a more common 18 housing and gear and be done with it?

If you have a #18 housing, your 17 tooth gear from Brattons should fit that housing and work well when mounted on torque tube, assuming you have the correct internal gear on the driveshaft. The #17 turtle housings are difficult to find.

If necessary, and I don't believe it will be, you could drum sand the radius area on the turtle housing ever so slightly to give that 17 tooth gear slightly more mesh with the internal worm gear.

On the next '35 rear I build with 3.54 gears, I will have to use a 17 tooth gear in a #18 turtle housing because that's all I have right now.