Stuck speedometer needle

[Alpine 1789]

I have long had a problem with my speedometer needle occasionally sticking. I will leave the house, drive a bit and look down and see that the needle hasn’t budged. This must be a common problem as I had it with a previous speedo and have seen other people have to do the same thing at Invasions. I have always assumed that I just needed to lubricate something, but forgot to do that when I cleaned everything up and repainted the needle last spring.

Taping the glass always unstuck it…at least until last night. Between the heat and my work on the O2 sensor, the car had been sitting for a week or so, maybe as many as two. I noticed the lack of speedo movement shortly after pulling out of the driveway, but increasingly hard taping did nothing. While I was working in the area of the speedo cable while installing the sensor, I don’t think it was ever in danger. I hate the prospect of lying on my back and removing the gauge; I’m getting too old for the contortions. But, I will certainly do so if that is the first place to start. Which brings me to my first question: Assuming that the cable still looks fine, is removing the speedo the first place to start? If so, does anyone recommend a specific fix? e.g., a particular place I should put a drop of light weight oil? Something else?

Thanks.

 

[sunbby]

I found this article helpful, you can obviously ignore all of the odometer stuff. My speedo needle chattered and sometimes stuck, I put a small amount of light oil on the 2 areas where the spindle rides, I can't remember if I just removed the face and squirted it in there or if I had to actually remove the 2 tiny screws and pull off the drag cup assembly, or maybe the gears came off of the back? If you do it, just be very careful of the hair spring and review the article.

http://home.comcast.net/~rhodes/speedo.pdf

 

[Alpine 1789]

Thanks Todd. I'll give it a try and report back.

 

[Tom H]

Jim, Todd's advice is about right. You may be able to improve it by slight adjustment of the screw you see in the middle of the mounting "bridge" in figure 9. That screw sets the amount of end play in the needle spindle. Don't make it too loose or the drag disk can move too far up and then you lose some magnetic coupling with the rotating magnet and it will read low. But just a slight turn will allow some play and stop sticking. Or maybe first grab the drag disk and pull/ push it in and out to see if you can feel any play at all. The most likely place to bind or stick is the bottom of that spindle, inside that brass bushing in the center of fig 5.

Tom

 

[Alpine 1789]

I never reported back on my success (or lack of) with the stuck needle as I went on vacation right after I got the car back together. I had removed the speedo before I left and unstuck the needle, but did not completely dismantle the unit per the instructions that Todd had posted. I didn't go too far because my web surfing on the topic had found the suggestion that Smiths speedos can sometimes stick if the stop allows the needle to go past 0. Mine did and I was hoping that was the problem. I straightened the stop and only had time for a quick drive before leaving on vacation. All seemed fine at that time, but I just drove the car today for the first time in about 3 weeks and it is stuck again. So, it looks like I have to remove it and do it completely this time.

Thanks to Todd's article I know what I have to do, my question is "do I have to do it right away?" It was so hot before I left that I haven't really driven the car in what seems like forever and I'd like to drive a bit before taking it apart again. I can use my GPS to keep track of the speed, but don't want to do any permanent harm to the speedo in the process. Will I?

 

[alpine_64]

I never reported back on my success (or lack of) with the stuck needle as I went on vacation right after I got the car back together. I had removed the speedo before I left and unstuck the needle, but did not completely dismantle the unit per the instructions that Todd had posted. I didn't go too far because my web surfing on the topic had found the suggestion that Smiths speedos can sometimes stick if the stop allows the needle to go past 0. Mine did and I was hoping that was the problem. I straightened the stop and only had time for a quick drive before leaving on vacation. All seemed fine at that time, but I just drove the car today for the first time in about 3 weeks and it is stuck again. So, it looks like I have to remove it and do it completely this time.

Thanks to Todd's article I know what I have to do, my question is "do I have to do it right away?" It was so hot before I left that I haven't really driven the car in what seems like forever and I'd like to drive a bit before taking it apart again. I can use my GPS to keep track of the speed, but don't want to do any permanent harm to the speedo in the process. Will I?

If you are worried you can always disconnect the speedo cable so its not trying to turn the speedo head.. just tie/tape it up under the dash so its out of the way.. then when you fix the speedo put it back in.

 

[Tom H]

I cannot imagine any problem from what you describe that would get worse from runnung while stuck.

when you do take it apart, push pull on the needle hub to verify that there is some - very slight- play. Just enough that you can actualy see or feel some in out motion.

Tom

 

[George Coleman]

2 cents worth, if you have had the speedo apart and the needle has been painted this may be the problem, I rebuilt my speedo about 15 years ago and still have this problem every now and then with the heat and all it seems to get worse, winter time no prblem, but it still works fine!

 

[Alpine 1789]

Thanks guys. The needle had been painted, but I am pretty sure it stuck occasionally before that too. (the one it replaced stuck, too.) As I said before, the only difference is that it used to 'unstick' with a gentle tap on the face. But that doesn't work anymore.

The summer/winter observation is interesting; I never noticed any heat-related effect, but the last few weeks were all in the high 90's, so that could have been a factor.

Its an OD speedo, so I will probably take Michael's advice, just to be safe. I'll report back after I get it out and try to fix it correctly.

 

[Nickodell]

Just an idea.

I took the bezel off my speedo to clean the plating and glass, and after replacing it and cinching the locking lugs, found the needle stuck at about 30mph. It was actually touching the glass. Seems that when I replaced the glass/bezel without a new rubber O-ring/gasket, it cinched down more than the clearance allowed. A new O-ring fixed it.

It may also have been that the needle was not replaced far enough down the shaft.

 

[Alpine 1789]

My new speedometer

Works like a charm!



p.s. Good thought Nick, although I know this isn't the problem as it worked fine for more than a year after I cosmetically refurbished it last spring. Like I said, it occasionally got stuck before and after that work, but it is only recently that a few gentle taps on the glass failed to re-start it.

 

[atallamcs]

Stuck Needle

Mine stuck at 120mph so I left it that way. Acutally if tapping does not work, a little compressed air around the glass and bezel often will find a way in and move around the dust or dislodge the needle contact with the glass.
Bill