MTFCA Forum

So I bought this speedometer at Luray. Trying to ID it. I can't find a company name one it. Unless it's AC. Anyone recognize it?
Is the large ring (I have one) universal?

It is an AC unit. Very nice. Vast majority are blown pot metal. Very hard to find one usable.

I'm reading about the problems with them now. I hope I didn't buy an expensive paperweight. Not sure how to test it. Could I hook up the cable and use a drill on the other end to spin it?

You could try the drill, but slow goes it in the correct rotation. Try rotating with your fingers first to make sure it is not binding up. There are other AC heads that will work with the setup you have. Just to be sure you know, it goes on the left front wheel not the right. No one that I have found rebuilds this type of AC heads. I used one like this when I had my AC setup; https://www.ebay.com/itm/373569013236?h ... ondition=4 There might be others that will work.

If you can turn the drive end & the dial rotates freely, its probably ok. Sure turn with a drill. You might consider sending to Russ F. to service & lube before running it.

The AC speedometer was made with pot metal internals, and at the time of production, no one expected these units to last, let alone work, after 100 years. Unfortunately, the pot metal used to hold the aluminum speed cup on a AC speedometer warps and swells, making the units unusable. You can determine if an AC speedometer is usable by checking out if the speed cup drops to zero easily, and when the speedometer is shaken gently, does the speed cup move easily. Unfortunately, you can see the speed cup on this AC is sitting at around 3-4 mph (not good). I always caution people about using a drill to see if the speedometer is "free", and I have had to rebuild speedometers from owners who had used a drill in this way. One hundred year old grease does not work too well, and it is just better to talk to a person who rebuilds/restores old speedometers BEFORE using the drill.

In all the years I have rebuilt speedometers, I have seen about a half dozen First Series AC units that worked following restoration.
Russ Furstnow

Thanks for the input everyone. I'll try the shake method and my fingers. Unfortunately as Han Solo said "I got a bad feeling about this." I may have made an expensive mistake.

Well what do you know. I gave it a little tap with my hand and it went back to zero. So I know I'm not out of the woods yet. Won't know until it's opened up.

Russ is the man. Have him look @ it.

Here is anothe r service https://www.bobsspeedometer.com/services/speedometers/

I too agree, send it to Russ or see what he has that will work for you .

Russ was kind enough to have me do a test. He said to use a drill and see if it jumps all over the place it's no good. I'm not sure if this is what he means so I'm hoping he'll have a look. It seem to move fast but is that because of the drill speed. I had the drill in reverse.

https://www.youtube.com/watch?v=Ww7UDNKUxSU

This is the video.

I couldn’t agree more with those that said send it to Russ, he will be straight with you on what you’ve got. With him, working on vintage speedometers isn’t a hobby but rather a passion.
Saw the video don’t do that any more, ha, seriously though.

Rob, After looking at the video, the speedometer cannot be repaired. The pot metal frame that holds the speed cup is either warped or broken, making the speedometer a "shelf" item. I'm sorry for the bad news. Russ Furstnow

Thanks Russ. Not what I was hoping for. Unfortunately I paid a large sum of money for it at Luray and with no way to tell if it was bad or not I bought it. I don't fault the guy that sold it to me he didn't know. He had it as a NOS unit and from the looks of everything I bet he was right. Unfortunately these things go bad over time. Too bad someone isn't casting the pot metal out of something better.

Well I gave Bob's Speedometer's a call to see what they do since they list AC as something they work on. I spoke to Bruce. He said that they do make the pot metal parts out of bronze as well as machine some of the original parts. However, it wouldn't be cheep. If he had to make the three parts in the spedo that are made of pot metal it would be around 1500.00. The big part of the price is time. Having worked on clocks before I know why it costs so much to have a clock serviced. Making everything right takes a lot of time. Russ' advice of putting it on the shelf is probable the best. Sadly I paid 400.00 for it and it was my mistake for not researching before I bought it. So am I mad? Nope. I don't think the guy who sold it to me knew there would be a problem. For now I'll go with my phone speedometer app and concentrate on getting Rattles back on the road.

All is not lost! You could recoup some of your money. You have the drive, cable & cog for the wheel, probably get a lot of your money back on those items.

If you are so inclined to have a functioning era speedometer, just call Russ back & purchase one of his rebuilt Stewart units - you'll be money ahead !!!

I think my best bet would be to just do that. Call Russ and buy a rebuilt one. I'll be selling the rest of the stuff later on. Thanks to all of you for your input and a big thanks to Russ for all the help.

I dislike the appearance of an AC speedometer. It's the same one that is used in a 25-6 Chevrolet.