Jumping/wagging speedometer

[gregidea]

The needle on my speedometer will read my speed, so long as I have continuous acceleration from a dead stop. As soon as there is a lag in speed, or I begin to cruise, the needle wags back and forth and continues to do so until I come to another stop. This started maybe 4 days ago. And today, I got a speeding ticket. It figures.

Has anyone experienced this before? The officer told me I probably had to lube up the cable...right after he handed me the ticket.

 

[pontiacgp]

you might want to ask Bonnewagon, I know he's repaired a speedo or two

 

[carmangary]

Yea, it's usually because it's sticking. The cable starts to act like a rubber band and as you twist on it it builds up tension until it sort of snaps and springs forward a bit and then repeats. If it's old it could be gunked up and the best thing is to replace it.

 

[gregidea]

Ok, I'll try replacing it. I figure if I have a receipt for a new part, they might just take it easier on me with the ticket perhaps.

Thanks for the quick reply.

 

[billyjack]

Disconnect it from the speedo, pull the cable out from the housing and inspect it. If it's not frayed, wipe it clean and rub a foot or so with a coat of common white grease, such as Lubriplate. Feed it back into the housing, coating it with grease as you go along. I feed it in with one hand while rubbing on grease with the other hand. Clean the excess grease from the end of the housing and bolt everything back together. Most likely you'll be fine for quite some time.

Bill

 

[pontiacgp]

if I were you I'd buy a speedo cable and keep the bill so that will show you had a problem a mechanical problem...then bring it back after if you don't need it. Even better tho is if you have anyone in a shop who can write you up an invoice for the repair to your speedometer cable. If you have no previous tickets that will help you as well.

and Bill, I didn't know you use speedos on dirt...

 

[billyjack]

and Bill, I didn't know you use speedos on dirt...

Speedo? Since there ain't no transmission to be found, there's nowhere to hook it up. If I could, I'd hook one up and have it recalibrated to read 20 mph slow. Maybe that would give the driver some motivation to keep his left foot off the pedal.
Hell, until about 2001, we didn't even run a tach!
When we could finally afford the big bucks for a used but fresh Kistler motor, we figured a tell-tale tach was good insurance. No time to check while on the track, but at least we could push the little button in the pits and see where it revved to. Can't get too fancy on gauges when your only power source in the car is a 9 volt radio battery.

Bill

 

[gregidea]

Ok, I bought a brand new cable, installed it, and it seemed to work. Got out on the highway with it, and the speedo still won't work over 35mph. So it seems the problem is the speedo itself. Can I fix it possibly? Can I replace it???

 

[Phoenyx]

It's probably the speedo head (I think that's what it's called). I don't know anything about gauges. But I called a few places to get mine fixed and they said they couldn't do it. Something about needing a special license because the odometer can be tampered with while repairing it. Best bet might be to find a junkyard speedo.

 

[burgundy83]

Mine wagged when I bought it, I pulled it out and greased it up, just like what was said above, no problems for 2 years so far