I have a stock speedometer in my 51. It was working fine until a couple days ago. It started making a horrible whining noise and the needle was jumping all over the place. When I stopped, it wouldn't return to zero.

My son and I pulled it out, verified the cable was good and properly seated and connected at both ends. All was good. The needle moved freely when we turned it by hand. Then we ran the cable with a drill. Everything operated normally until about 40 mph or so, then it went nuts again.

I talked to our local speedometer shop and the guy says he can fix it. Says it will be $85 plus parts etc and since its an antique, it could easily be $200ish.

$200 is not a catastrophe, but if I can fix it myself with a $2 spring or a $5 magnet I'd rather do that. I've pulled open the unit and separated the face and the back, but have not opened up he inner workings.

So my quandary is this: if I open it the rest of the way, am I going to find a soup sandwich of a hundred fiddly little parts and end up with a mess? Or is it simple and easy to deal with?

If it's complicated and lots of tiny parts that are hard to manage, then I'll take it to a professional. If it's not too bad, maybe I'll do it myself. I just don't want to open it up, only to have have a bunch of springs and gears fall apart in my hands, then be stuck.

Any insight on this would be appreciated!

Thanks! Tyler

 

I have not opened one, but if you open yours and need a part let me know. I have one that I bought for parts and all I need is the housing, face, and pointer, the actual speedo mechanism you can have. Should fit in a $5 priority mail box.

 

Hey, cool. I'll pm you! Tyler

 

Cold weather and a dry cable will act this way. The cable vibrates and sets up the oscillation. Since you have the unit in your hand. Try some very light lubrication on the brass bushing where the cable fits. Put a drop of lub on each end of the odometer mount and on the gears that drive the odometer. Another drop on the bearing surface where the needle swings. Unless you see obviously broken parts, you're done with the head.
Now that you've serviced the head, focus on the cable. Pull the cable out of the housing and hold each end. Rotate the cable between your thumbs and forefingers. Vary the distance between your hands while doing this. If it is good the cable will roll smoothly with no irregular jumps or kinks. If it does not roll smoothly, replace it. Make certain the housing is not kinked or damaged. It will not hurt to dump some cleaner through the housing and let it drain. Clean the housing with compressed air. Lubricate the cable with graphite lubrication and re install the cable.

 

Ok I'll do that. Thanks! T

 

Ray is spot on about cleaning and lubing the mechanism and the cable. On my 54 and I would assume on your 51, there is a hole for a few drops of lube oil on the stem of the speedo head. I this it is called a weep hole. After you have done what Ray told you make sure you lube periodically through this weep hole.

 

3 in 1 oil works excellently for speedometer lubrication

 

Thanks guys! I was gonna ask what type of lube to use but you read my mind! Peace T.

 

Let me know if yours works after lubricating, I checked mine and the back is packed with dirt. It may work but I don't have high hopes.

 

Ok, I'll let you know. I may still want it for a few parts.

 

Hey guys, a couple questions on this. I've lubed the speedometer head as suggested above (have not yet messed with the cable, but it is brand new and so is the housing, connection at trans etc, so I doubt it's the problem).

Anyway when I move the needle by hand on my bench, there seems to be a little resistance or drag in there somewhere. Is that ok?

Also, when released, the needle will not return to zero. Should it return, or should it just stay where I left it? (Also on the bench, not installed).

Thanks! Tyler

 

The needle is held in the 'home' position by a fine spring so yes, you'll feel slight resistance. If the needle is in the vertical position, as mounted in the truck, the needle should be against the home pin. If you rotate the input to the head you should see movement to the needle and then the needle should return home. If it does not return home, you have a problem, either damage or dried lubrication.

 

Yeah, unfortunately I think I have more of a problem. The resistance isn't smooth resistance from a tiny spring, it's more like slightly rough friction from metal to metal contact inside the drum or barrel or whatever it's called.

When I grab the needle itself and move it clockwise around the speedometer, then let it go, it does not return to home or zero.

I'm gonna punt on this one and take it in for repair.

Thanks! T

 

Hey Dave, I think I want that speedometer. I sent you a pm. Thanks! T

 

Mine failed in the same way. The bushing inside for the spindle gets sloppy, then the two parts that are supposed to be rotating close to each other can actually touch, sending the needle towards the peg. They are supposed to be lubricated regularly but who does??

Since you have the stylish '51-'52 dash, you can still find brand new OEM speedos. They were used in parcel vans (bread trucks) until into the '60's. Ones I've seen on eBay were less than the cost to repair.