Speedometer issues

-

haybag

Well-Known Member
Joined
Dec 14, 2014
Messages
192
Reaction score
17
Location
New Hampshire
Just got my 69 Dart together and took it for it's first test drive. Speedometer is all over the place.As soon as the car is moving it bounces wildly from 0 to 120 and the faster the car moves the faster it bounces. At one point it stuck at 70 even when stopped then went back to bouncing and the next time I stopped was back at 0. Has a new cable and I checked routing and there are no kinks or binding. Had bench tested the speedometer and cable and seemed normal before installing. Odometer seems to be accurate. I am assuming that it is the speedometer itself that is the problem but want to get some opinions before I get into it.
 
When you get into it you'll see a magnetic gyroscope like assembly. One part spins inside another. Look for shinny rub marks on the outside of the drum shaped part, evidence that one part is contacting the other. It might be that cleaning the hardened contaminated grease crud from the square input port and routing the cable into it as straight as possible will help but that's only if all the wear in in that shaft/bushing fitment. If the wear is in the two small bushings that the drum/needle post assembly runs in, send it out for restore or gamble on a used one.
 
Just got my 69 Dart together and took it for it's first test drive. Speedometer is all over the place.As soon as the car is moving it bounces wildly from 0 to 120 and the faster the car moves the faster it bounces. At one point it stuck at 70 even when stopped then went back to bouncing and the next time I stopped was back at 0. Has a new cable and I checked routing and there are no kinks or binding. Had bench tested the speedometer and cable and seemed normal before installing. Odometer seems to be accurate. I am assuming that it is the speedometer itself that is the problem but want to get some opinions before I get into it.

The damn things are pretty particular about the cable angle also.
I put the car on stands and move the cable around until I get it in a place it likes.
Any sideways pull on the cable has a huge affect on the speedo head.
 
If you have a new cable in it, and it is lubed, then you have a problem in the head.
 
Not always.

The inner cable does not always 'engage' into the socket properly.

I had a new one doing a similar thing on a '71 I had. So I took it loose from the transmission & put light pressure on the inner cable while pushing it up the sleeve.

It moved up about a 1/2 & into the speedometer socket & fixed the issue.
 
Just got my 69 Dart together and took it for it's first test drive. Speedometer is all over the place.As soon as the car is moving it bounces wildly from 0 to 120 and the faster the car moves the faster it bounces. At one point it stuck at 70 even when stopped then went back to bouncing and the next time I stopped was back at 0. Has a new cable and I checked routing and there are no kinks or binding. Had bench tested the speedometer and cable and seemed normal before installing. Odometer seems to be accurate. I am assuming that it is the speedometer itself that is the problem but want to get some opinions before I get into it.
I cleaned and lubed everything in mine , back when I started my build. Nothing appeared to be worn (to me) , cable engages good on both ends and is in the stock location ,it bounces about 10mph , Kinda pic the in between ____________
 
-
Back
Top