Speedometer Fluctuate?

[Astro409]

I doubt this is a rare problem as i've seen many older cars with the same problem as my 1964 Impala. My speedometer won't stop moving even when we are at a constant speed. The needle acts as if my speed is going up and down when in reality i'm traveling at the same speed. What is it that causes the speedometer to fluctuate constantly? Thanks

 

[Aqua 409]

You may have already check these, but if it is a 5-10 mph fluctuation there is a possibility that there is a slight kink or a little to sharp of bend in the speedo cable between the transmission and the speedometer or the cable may be a little dry and need to be lubricated.
Ralph

 

[dq409]

I also have a problem with flatulation but all the lubing hasn`t changed a thing !!

 

[Ronnie Russell]

I suffered the same problem. Had a spare instrument cluster from a parts car. Changed the speedometer head and problem fixed. Evidently that symptom is a bad head. By head, I mean the main speedometer unit.

 

[bobs409]

I would disconnect the cable from the back of the speedometer and pull the cable out of the housing. Fish it into a quart of trans fluid, then while pulling it back out, lightly wipe the excess off and then reinstall. Most times that will take care of it.


Bob

 

[Impalaguru]

If it's doing what you say, sooner or later it will start going past 120 and making a horrible screeching noise!! I had it happen on my 63. It would only do it when I would drive it in temps below 20 degrees. Finally the needle broke off!!! I pulled the cluster, glued the needle back on and put some dry graphite in where the speedo cable connects. It was quiet after that.
For now, I would just unhook the cable.
Ross
PS I'm still waiting on the little tube for your air cleaner.

 

[Astro409]

Thank you

Thanks for the info. I'm going to try a few of the things and follow some of advise that was shared hopefully this weekend. I can tell you that not one was something I was thinking on trying.no1: But they make alot more sense then my crazy ideas. I was going to check the speedo gear for a broken tooth or try a new cable and finally try a complete speedometer housing from my other Impala to see if it was a problem there:eek: but your advise makes more sense. As always, thank you very much.

 

[Astro409]

If it's doing what you say, sooner or later it will start going past 120 and making a horrible screeching noise!! I had it happen on my 63. It would only do it when I would drive it in temps below 20 degrees. Finally the needle broke off!!! I pulled the cluster, glued the needle back on and put some dry graphite in where the speedo cable connects. It was quiet after that.
For now, I would just unhook the cable.
Ross
PS I'm still waiting on the little tube for your air cleaner.

No rush on the air cleaner. However Ross, what are you doing driving your toys below 20 degrees?:eek: no1: That is garage temperatures for my Impalas.

 

[Impalaguru]

I had two bad winters, in a row, when I was in college, when my daily driver quit on me!! But, my 409 NEVER, EVER quit on me!! I drove that car EVERY DAY for 7 months, while I fixed my other car. I've driven that car through every kind of weather you can imagine. High heat, below zero temps, heavy rains, snow, sleet. She took it all like a champ! And that was all when the car/engine had over 165,000 miles!
Ross

 

[Astro409]

when my daily driver quit on me!! I drove that car EVERY DAY for 7 months, while I fixed my other car.
Ross

Now that you mentioned this, I did bring out one of my toys out of storage. Actually, it was my only toy at the time.: It was a 1970 Chevelle with drums in the front. Not good on icy weather. My daily driver a 1985 Cutlass wouldn't stay on and the Chevelle came out to the rescue. I think the brakes were even harder that icy day.

 

[Nuts]

I like driving my car in the winter, on good days. Only time she doesn't overheat...