MTFCA Forum

The driven gear for the speedometer needs replaced. The odd thing is it's a 17 tooth gear and all of the replacement ones I can find are 16 tooth. I have no idea of what it was originally on as I found a receipt from when the guy that restored my T bought the whole package at a swap meet back in 1980. I think he paid $100 for it. If I have to I'll draw up a gear in Solidworks and make it.

While I have the drive pulled off, what maintenance should I do to the drive and cable?

Todd, I'd take the swivel apart and clean and re-grease all the bits. BE AWARE, the output shaft is held in the housing with a tapered pin. If you try to drive it out against the taper, you will smash the housing. If you are happy to just soak it while still together, then leave that part assembled.
I would do the same to the cable and housing, clean and re lubricate. With luck, your parts will be able to continue to function for you.

Allan from down under.

Contact Russ Furstnow and discuss the correct tooth count you need before you go to the trouble of making a new part.

I drew up the same gear using Onshape 3D. Happy to share the stl file (or any other format) with you if you need it.
3D prints of this gear work really well. I have over 1000 miles on mine and it still looks brand new.
I've only seen these gears in 16 teeth.
https://modeltstarters.com/product/stew ... eter-gear/

Jeff

The pinion gear for a Model T should be a 16T8P gear with a 60T8P Raod wheel gear (with 30X3 1/2 tires). The swivel should be taken entirely apart to clean out the 100 year old grease. Disassembly of the swivel can be found in my speedometer book published by the MTFCA. I hope this helps. Russ Furstnow

Could be whoever put it together did not know or did not have the correct gear and used what they had on hand.
Chain should be pulled cleaned and regreased too.

AdminJeff wrote: ↑

Mon Mar 11, 2024 12:34 am

I drew up the same gear using Onshape 3D. Happy to share the stl file (or any other format) with you if you need it.
3D prints of this gear work really well. I have over 1000 miles on mine and it still looks brand new.
I've only seen these gears in 16 teeth.
https://modeltstarters.com/product/stew ... eter-gear/

Jeff

Thanks for the offer. I looked at the gear you have available when I ordered my voltage regulator. I'm going to see what the gear wizard in Solidworks spits out when I input the pitch and number of teeth. I have access to a waterjet cutter, so it shouldn't be too bad to make. I keep looking for a good excuse to buy a 3D printer, though.

Russ_Furstnow wrote: ↑

Mon Mar 11, 2024 12:01 pm

The pinion gear for a Model T should be a 16T8P gear with a 60T8P Raod wheel gear (with 30X3 1/2 tires). The swivel should be taken entirely apart to clean out the 100 year old grease. Disassembly of the swivel can be found in my speedometer book published by the MTFCA. I hope this helps. Russ Furstnow

Thank you for the input. I'll get the book so I don't break anything while taking it apart. I counted the teeth on the large gear last night, it has 64 teeth. If my math is correct, the two ratio's are very close. 60/16 = 3.75, 64/17 = 3.765. We checked it with a iphone speedometer app last summer and it was close enough for us. As I said previously, I found notes in the stuff I got with the car that this speedometer assembly was bought at a swap meet back around 1980, so who knows what its history is.

Allan wrote: ↑

Sat Mar 09, 2024 7:15 pm

Todd, I'd take the swivel apart and clean and re-grease all the bits. BE AWARE, the output shaft is held in the housing with a tapered pin. If you try to drive it out against the taper, you will smash the housing. If you are happy to just soak it while still together, then leave that part assembled.
I would do the same to the cable and housing, clean and re lubricate. With luck, your parts will be able to continue to function for you.

Allan from down under.

Is there any special grease I should use in this?

Russ_Furstnow wrote: ↑

Mon Mar 11, 2024 12:01 pm

Disassembly of the swivel can be found in my speedometer book published by the MTFCA. I hope this helps. Russ Furstnow

I picked up a cop of your book on ebay. Great book with very helpful instructions! Thanks for letting me know that it exists.