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Stewart Speedo drive ID

Posted: Sat May 23, 2020 10:17 pm
by Retro54
Along with my 1915 cut down touring, came some boxes of parts. In those parts were these Stewart speedometer drive gears and drive itself. I do not have the speedometer itself, or the cable. Was hoping the experts out there could help me discern what I have or point me in the right direction of reference materials. My body is a January 1915 Beaudete body if that helps at all. My hope one day would be to acquire a head and cable for the car after I get the car back together and on the road (priorities!) But in the meantime it would be nice to know what to look out for. Thank you in advance for any expertise that can be provided!

Re: Stewart Speedo drive ID

Posted: Sat May 23, 2020 10:19 pm
by Retro54
Here are photos of the drive and fiber gear. The spindle for the fiber gear has what appears to be a '40' cast into it.

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 12:38 am
by Susanne
The big gear is the wheel gear... it mounts to the hub bolts of the right wheel.

The swivel mounts to a standoff on the spindle... depending on which speedo someone put on the car (1915 was the first year Ford did NOT put a speedo on his cars, but sold them at dealerships as accessories) it will either be a 1:1 or a 2.5:1 ratio at the swivel... the fiber gear on the swivel is a replacement - it's likely the original got chewed or broken in service (which happens - all it takes is one piece of gravel in the wrong place at the wrong time)...

The cable (which was originally a chain - seriously - tho few have not been converted to the more modern replacement) goes in a steel (not brass) housing which is painted black. When you get your speedo head (which screws to the right side of your firewall) make sure your cable is not only tight but I recommend using loctite on the threads (and maybe a ziptie or 2 to make sure it stays in place) - I had my cable come off my speedo head on the road and the housing was ingloriuosly run over breaking both it and the swivel during an afternoon drive.

The important thing is that speedo head, swivel, cable, and road wheel all match. Otherwise you look at your speedometer saying 54 MPH at 32 MPH (or vice versa - I don't remember which way it skews) or it drives the wrong way...

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 1:24 am
by Allan
The missing bits to mount the swivel are available from the vendors, but with time on your side you should be able to find original bits cheaper. There is a U bolt/strap which holds a riser to the spindle arm. Then what you have mounts on the riser. The head may be easier to find than the cable. All you need is the outer cable and a modern inner and outer cable can be run inside it.

Hope this helps.
Allan from down under.

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 8:57 am
by Russ_Furstnow
For the 1915 model year, Ford Motor Company contracted with five speedometer manufacturers (Jones, Sears Cross, Stewart Warner, Standard Thermometer and Johns-Manville) to produce a speedometer for the Model T. The 1915 speedometer is known as the Ford Special and is the only speedometer made by various manufacturers that has interchangeable parts. The Ford Special was an accessory item on the 1915 Ford and in July 1915, Ford stopped installing a speedometer on the Model T. The speedometer used a direct drive (no swivel) and "modern type" inner cable. I've attached some photos of the speedometer and its drive parts. I hope this helps. Russ Furstnow

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 8:59 am
by Russ_Furstnow
Here are the speedometer heads.

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 9:04 am
by Russ_Furstnow
The Ford Special was a "factory" accessory, but there were other manufacturers that offered speedometers to owners and dealers in 1915, so speedometers other than the Ford Special can be found on original 1915 Model T's. One interesting note, the passenger side engine pan on the 1915 Ford is unique in that it has a 1" hole directly behind the carburetor drain hole to allow the speedometer cable to go to the drive. This hole is not found on other engine pans. Russ Furstnow

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 9:11 am
by Mark Gregush
Doesn't that fiber gear have too many teeth for the standard 2-1/2:1 setup?

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 9:18 am
by Russ_Furstnow
Standard Thermometer also made a 60mph Ford Special.

The Ford Special setup has a 12T8P fiber pinion and a 35T8P road gear...all unique to the Ford Special. The swivel that is shown in a previous post does not fit a Ford. Also, I left out one part that is seldom seen on Fords with the Ford Special setup, and that is the cable support. The cable support hangs from the right fender support to the cable and keeps the cable from rubbing the front axle. Here is a photo of this important item.

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 10:42 am
by Original Smith
Thanks Russ for posting those pictures. It could be some folks are not aware of your speedometer book. Those photos are perfect!

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 10:43 am
by Original Smith
I failed to mention, Randall Anderson makes the cable support.

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 8:57 pm
by Retro54
Thank you Russ and Original Smith!

Russ. The fiber head I show was actually mounted on my car, I do not necessarily imply that it us original to the car, only that it was on the car when I got it, but the ring gear was not. Photo below.

This car has many unique accessories (as maybe you can see from the extended front spring perches in my photo)

I am certain that the January 1915 touring body came with a speedo, as seen by the floor board photo below having both a horn cut out, but also the speedo cut out. The firewall also shows signs of the speedometer being mounted.

Now, I wonder what this ring gear and fiber gear go to if not a Stewart Warner part meant for a Ford?
Russ, is your book available thru the MFTCA website?

Re: Stewart Speedo drive ID

Posted: Sun May 24, 2020 9:30 pm
by Allan
Andrew, your last photo shows some interesting details, including the accessory over length spring. The way the speedo drive is mounted shows some ingenuity, but it is not usually done that way. The hole in the spindle arm is tapered, and usaually accepts a right angled rod, with a corresponding taper, mounted from the top. I suspect the speedo set-up you have is one cobbled together using whatever parts the owner had access to. The combination of gears you show is unusual, the fibre gear being way too big for any standard Ford application. This would suggest the swivel ratio is also different. It may well have worked, but it will take some fiddling to get it to do so again.

Allan from down under.

Re: Stewart Speedo drive ID

Posted: Mon May 25, 2020 8:24 am
by Russ_Furstnow
Andrew, Your swivel joint and fiber gear could have been used on anything, but NOT a Ford. The Ford Special drive mount fits in the tapered hole in the spindle arm as Allan explained. If you would like to purchase a book, I have them for $30 plus $8 for shipping. I hope this helps, Russ Furstnow

Re: Stewart Speedo drive ID

Posted: Mon May 25, 2020 11:42 am
by Mark Gregush
Here are the part to mount the swivel type drive that you have;
https://www.modeltford.com/item/2740S.aspx
To mount the wheel gear;
https://www.modeltford.com/item/SP-WS.aspx
The swivel gear;
https://www.modeltford.com/item/SPG1.aspx
The wheel gear you have may or may not fit down around the hub you show in your photo. Do ether of your hub have a machined area around the inside edge? The wheel gear you have can be mounted in two ways, with screws and spacers shown in link above to wheel spokes or with screws and spacers to the hub it self (like the ones like the ones shown in above post for the Ford special). I have the wheel gear like you show, but with just the inner set of holes. It fits down around some hubs without the machined area, but not others. There was a tool made to locate the screw holes if mounting to the spokes to keep the gear centered.
The spacers that mount the gear to the spokes are 3/4" tall so when you try your gear to see if it fits down around the hub you will be able to tell it if works or not. If it does not, you would need the wheel gear that does not have the spokes and inner mounting ring to use with the hubs you now have.
Without knowing the number on the swivel, it may be correct for the 8P60T gear that mounts on the wheel, but not with the fiber gear that is on it now. I would suggest giving a good clean and see what number you can find. Let us know then we can go from there. Someone may have cobbled something together and worked in the ball park re the MPH shown on the speedometer.
Getting and mounting the Ford Special type speedometer would require all different parts then you don't have on hand at this point, in fact the only part you show that would work is the spindle arm and might require a machined hub also. Also going with the parts you have on hand now, gives a lot more choices for the speedometer itself, if you are not building a points car and just want a speedometer. The Ford Special type speedometers(there are several brands) are not as common as the later speedometers that would work with the 8p60T gear and swivel (if it's the correct one, model 1913) that you have now. Try googling "mtfca speedometer"

Re: Stewart Speedo drive ID

Posted: Mon May 25, 2020 9:32 pm
by Retro54
Marl, thank you for the awesome information download. You cleared much up for me, along with previous posts of course. I'll need to spend some time with the swivel and see where it gets me.

Thank you!

Re: Stewart Speedo drive ID

Posted: Tue May 26, 2020 12:11 am
by Mark Gregush
Great. After you do some cleaning and checking add to this post so we can keep track of what has been posted already.