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speedometer rubbing

Posted: Sat Sep 30, 2017 10:10 pm
by hmaynord
for many years, once I got over about 30, needle would go over to 80 or so, fluctuating 10-15 mph.
odometer is fine, except for the larger tires I put on it in the 70s, but that's another story.
opening it up, I see there is no physical connection between the cable and the needle:
the needle is connected to a drum that is held at zero by a spring,
the cable is connected to 2 pieces 180 degrees apart, each in the shape of a "U," with the edge of the drum sitting inside of the "U":

https://www.dropbox.com/s/bd13znxzo11p2 ... g.jpg?dl=0

I guess under normal conditions, the rotating "U"s create a magnetic force, which causes the drum to overcome the spring tension by the proper amount.
The problem: I don't know if you can see it in the photo but, periodically throughout the rotation of the "U"s around the drum, part of a "U" momentarily rubs on the drum, creating extra force against the spring, so 35 becomes a fluctuating 80.

I've got another speedometer head, but its odometer is about 40K off.

Thinking that I've got nothing to lose, maybe I could sand down the part of the drum that is catching. maybe have the vacuum going to try to keep grit out of the odometer gears. Suggestions?

Re: speedometer rubbing

Posted: Sun Oct 01, 2017 12:00 am
by ozzie
you can take the other speedo head apart, and reset the mileage.

Re: speedometer rubbing

Posted: Sun Oct 01, 2017 7:57 am
by hmaynord
ozzie wrote:you can take the other speedo head apart, and reset the mileage.
you can do that without removing any rivets?
just pop one end of the odometer out of the slot and remove it?

Re: speedometer rubbing

Posted: Sun Oct 01, 2017 8:29 pm
by ozzie
YEP, then turn the mileage where you want it, and slide it back in.

Re: speedometer rubbing

Posted: Sun Oct 01, 2017 9:16 pm
by hmaynord
thanks ozzie. exactly what I needed to know. :clap
I guess this goes back to the days when used car salesmen got their reputation.

Re: speedometer rubbing

Posted: Mon Oct 02, 2017 9:05 am
by ozzie
I can't believe they actually did that. (wink, wink). :lol: