New Speedometer Drive Worn out in 60 miles?

[Duke]

Has anyone else had a new speedometer drive wear out right away? This is a 18 tooth drive, I bought it as a complete unit from a reputable supplier. Car is a new build, late 1932 torque tube. Is there something wrong in my setup or is this a repo parts problem. It worked very well at first, but died after 60 miles. I likely have some metal fillings in the torque tube now.

[Kurt in NJ]

Looks like it wasn’t meshing fully.
I just put a 18 tooth in place of a 19 the 2 housings had a different centerline for the shaft.
I think the gear is nylon on the reproduction ones

[Duke]

This one was a steel gear. Came as a full unit.

[cas3]

The turtle shaft hight changes with different size gears, (ratio) So, if someone put the wrong gear in a turtle it would not mesh correctly. A possibility.

[petehoovie]

Originally Posted by Duke

Has anyone else had a new speedometer drive wear out right away? This is a 18 tooth drive, I bought it as a complete unit from a reputable supplier. Car is a new build, late 1932 torque tube. Is there something wrong in my setup or is this a repo parts problem. It worked very well at first, but died after 60 miles. I likely have some metal fillings in the torque tube now.

[glennpm]

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Originally Posted by cas3

The turtle shaft hight changes with different size gears, (ratio) So, if someone put the wrong gear in a turtle it would not mesh correctly. A possibility.

I think this is the case too. What is the number on the outside of the turtle? How many teeth in the worn unit?

[Duke]

This is a reproduction unit with no numbers. It came as is, ready to run. So it likely a faulty part and not something in the driveshaft set up?

[glennpm]

With the turtle off, look at the teeth on the driveshaft gear which is easily viewed. This recent thread has some pictures and guidance.

https://www.fordbarn.com/forum/showt...ghlight=turtle

[Duke]

Everything looks really good besides the turtle. I installed a 19 tooth original that a friend gave me. Will see how it does. If anyone has an original 17 or 18 tooth please let me know.
Thanks

[glennpm]

The turtle will take a one tooth change without modification. For two tooth difference, buy another turtle or grind to fit or by adding gaskets between the turtle and the torque tube.

Do you know the rear-end gearing? See this post to pick the correct tooth count in the turtle.

https://www.fordbarn.com/forum/showp...12&postcount=7

[Duke]

I have 3.54 gears with 7.50x16 tires. I am going to try to stick with a complete and original turtle.

[hueyhoolihan]

Originally Posted by glennpm

The turtle will take a one tooth change without modification. For two tooth difference, buy another turtle or grind to fit or by adding gaskets between the turtle and the torque tube.

Do you know the rear-end gearing? See this post to pick the correct tooth count in the turtle.

https://www.fordbarn.com/forum/showp...12&postcount=7

i may have to replace my turtle due to stripped threads...so this thread interests me.

so can i assume that if i replace my turtle with a new turtle with the same tooth count, i will, most likely, not experience the problems outlined by the owner of this thread?

the only reason i ask, is that if the answer is "yes", then i need to remove the old turtle and count its teeth before ordering a new one.

[glennpm]

Yes, if the damaged one reads correctly. I would definitely count the teeth since they may have been changed out.

[cas3]

striped threads on the torque tube?

[hueyhoolihan]

Originally Posted by cas3

striped threads on the torque tube?

the speedometer cable has knurled nuts that screw on to male threads at each end. one of the nuts threads on to the dashboard's speedometer gauge, the other nut to what is being, i think, referred to in this thread as "the turtle".

i was referring to the male threads on the turtle as being stripped, although cross-threaded would probably be more accurate. i won't be certain unless and until i get it off and have a closer look at them.

[Duke]

I paid $85 for the aftermarket drive. I am only buying a Ford one next time.

[rockfla]

Originally Posted by Duke

I paid $85 for the aftermarket drive. I am only buying a Ford one next time.

Here is an "Gennie" 18 on ebay right now


#176979558589

[hueyhoolihan]

here's a few pics of the one i just removed from my new-to-me 1941 deluxe.

as you can see the damaged connector and stripped threads, as i imagined, were what was preventing me from threading the speedometer cable back on the other day. i'll be needing a new one. and because the old one is labeled "18" on top, i'll be ordering an 18 tooth one from here: https://thirdgenauto.com/product/new...ly-3-54-ratio/

[petehoovie]

Originally Posted by hueyhoolihan

here's a few pics of the one i just removed from my new-to-me 1941 deluxe.

as you can see the damaged connector and stripped threads, as i imagined, were what was preventing me from threading the speedometer cable back on the other day. i'll be needing a new one. and because the old one is labeled "18" on top, i'll be ordering an 18 tooth one from here: https://thirdgenauto.com/product/new...ly-3-54-ratio/

[glennpm]

Count the teeth before you buy.