Speedometers

[vping]

Should a '25 Tudor Sedan have a speedometer like this if at all?

[RajoRacer]

I believe so - all speedos were accessories by that time - Stewart most common - AC also available.

[Mark Gregush]

If that AC speedometer still works that is a plus. Most all of them, the pot metal casting inside goes bad and is not repairable.

[vping]

Sorry I should have posted that the picture I showed was a screen shot from online. I currently do not have a speedo and just noticed that there was a place for it on the dash that was covered up. I can also see a slot behind the dash where something should be.

[jiminbartow]

[vping]

Are parts 3, 4, & 6 needed to hook up a speedometer on a '25?

[TWrenn]

Are parts 3, 4, & 6 needed to hook up a speedometer on a '25?

Reckon so. Get hold of Russ Furstnow if you can...he's the Forum's resident speedometer expert.

[Rich P. Bingham]

Not 3. That's the clutch pressure ring inside the transmission.

[TWrenn]

Not 3. That's the clutch pressure ring inside the transmission.

Whooops Rich! LOL...you're right about #3...wasn't payin that much 'tention!! My bad!

[RajoRacer]

Verify your wheel size - you'll need the appropriate road gear - 23" wheel takes a 60 tooth - 21" takes a 58 tooth - pinion the same - 16 tooth - 8 pitch.

[Allan]

Buy a copy of Russ Furstnow's book on speedos. While you do need a swivel like the one in No 6, the angled one shown is not usual. The swivels also come with different drive ratios. Most T's used a 2.5:1 ratio. They also come left and right hand drive, depending on which wheel it is installed.

All of this also depends on the brand of speedo you have to mount. My Corbin unit, as supplied by the dealer, uses a cast iron 1:1 ratio swivel. I would first find a suitable instrument as fitted to a T, and then go looking for the components you need to mount and drive it. The book will be an invaluable guide.

Allan from down under.

[jiminbartow]

Parts 4 and 6 are needed. Parts 1, 2, 3 & 5 have nothing to do with the speedometer. You will need 3 wood screws and spacers for attaching the gear to the wheel and a proper armored cable for sending the information from the sending unit to the speedometer. The gear diameter and gear ratio on the wheel gear needs to be the proper ratio for the speedometer and front right wheel you are mounting the gear and sending unit to, or the speedometer will give you the wrong speed and the wrong mileage. Russ Furstow will know what you need and might possibly have one to sell. He also repair speedometer that have stopped working due to swelled pot metal parts. I bought complete 160 and a 490 speedometer sets from him about 20 years ago. While I wanted to use the Model 160 because it looked nicer and had more functions, I ended up using the Model 490 set when I discovered that, due to the cowl tank behind the dash, the 160 would not fit. Jim Patrick

[Allan]

I was told to avoid Stewart speedos which have numbers painted on the tumblers. Many of these have paint flaking off, but the worst of it is the tumblers are diecast potmetal which swells and is impossible to repair. The advice was to find a head with tumblers where the numbers are etched/cast/engraved into the tumblers. These are serviceable.

Allan from down under.

[TMiller6]

The AC speedometer pictured is a different animal from all the other speedometers. The fiber driven gear is cupped and laminated between two pieces of steel. There is no gear reduction or swivel and the drive gear on the wheel has rectangular holes instead of teeth.

If I recall correctly, it also drives off the left wheel. I can take a photo of mine if I remember.

[Allan]

Which is why I suggested you first get your speedo head, and then went searching for matching components. There's lots of different stuff out there and most is incompatible between brands.

Allan from down under.

[jiminbartow]

I have never heard anyone or any source suggesting that we avoid the Stewart Warner speedometer as they are the most desired and best quality speedometers of the Model T era and were recommended by Ford. Anyone who would suggest avoiding a speedometer due pot metal parts that swell with age, might as well suggest that we avoid all brands of speedometers from the Model T era since virtually all speedometers from that era have pot metal cylinders that swell with age. Stewart Warner is a superior speedometer once the pot metal cylinders are replaced and Russ Furstow has the correct parts and expertise to do that using molded plastic cylinders with permanent colorfast numbers. My speedometer is a testament to that and unlike many other speedometers, is correct for the Model T. I would have nothing else.

[Allan]

James, you have hit the nail on the head nicely. The Stewart speedos with the plastic tumblers are serviceable, and that is the one Russ sold me. Those with the potmetal tumblers are often not rebuildable, even if they can be dis-assembled. Ford did recommend them, but what contra deal may have been made on that score.In their day they did the job, but they are now 100 or so years old.
There were much better quality speedos available in the model T era. Duncan and Fraser here in Adelaide only offered Corbin units. These used a cast steel swivel, cast link chains with wear ridges on the spacers and featured a brass carriage and components for the mechanism in the speedo head, like quality clocks of the time.. Mine is rock steady in operation, and rises through the range smoothly. They were the unit of choice on Harley and Indian motorcycles, where operating conditions were far more severe.

Allan from down under.