Need advise Speedo needle dancing

[71dodgechargerrt]

Went for a cruise to top up tank for winter storage and the speedo needle was dancing all over the place, the odometer was turning as normal. Is this a cable issue? Lube? The speedo gear at the transmission or speedo at the dash? 440 4 speed...Thanks

 

[Sixpactogo]

More than likely, it is the speedo itself. They get dried out more often than the cable does

 

[Grabinov911]

Not to disagree but I have twice had this issue and both times it has been the cable. The first time I spent a bunch of money to have the speedometer repaired at Hollywood Speedometer. they are legendary for this stuff and the thing came back beautiful, but it still bounced. I eventually replaced the cable and it got somewhat better.

Just recently I put in a Gear Vendor overdrive which required a modified speed sending unit which uses a cable. I am using it to send a signal to a Dakota Digital speedometer - no moving parts, totally digital, worked perfectly and smoothly unit the cable. Now EVEN IT bounces all over the place. I can't stand the cables, and this one is only 12 inches long. I'd tell you to get a new cable, but that may or may not work. It's a frustrating problem.

I'd say replace the cable but when installing it make very are not to bend it too tightly. I did during my installation, for just a second, and I maybe just a bit too far, and I think I may have kinked it. I wouldn't bend it tighter than say the radius it would take going around a soccer ball - even during installation.

 

[moparmarks]

Check and lube your cable first but I have had this happen to several 71-2 B-body and it was usually the speedo. The old grease is dried out and the nylon gears are binding against each other. I been able to lube the gears without taking the speedo apart but do have to remove it from the dash. Remove the speedo and clean out the old grease as best as you can. Then spray some good lube down the end of the shaft and with a small screw drive turn the speedo. Keep doing this until it gets loosened up. You can also spray some lube on to the gears with one of those red nozzles. Did this to my 72 daily drive a few years ago and is still working good. Have done this the a few customers B's and E's with good results.

 

[slepr1]

Whatever you do, do it soon. Don't let it wait too long. I had that issue and it was my cable. I put it on my list of repairs but didn't get to it soon enough and it unwound and broke the speedo needle off! :tongue9:

 

[idrivemopar]

Had the same issue, turned out it was the cable, it got melted on the exhaust and caused the problem.

 

[Sixpactogo]

You should be able to verify if the cable is the culprit. Unhook it from the transmission and turn the cable by hand. It should turn freely and not bind up. If you feel it bind up, it could very well be the cable. If it spins freely, it is speedo.

 

[moparmarks]

Actually check the cable out first. If the speedo is bouncing then it is probably the cable. If it is chattering then is probably the speedo.

 

[khryslerkid]

Turn your radio down so your speedometer won't dance!

Seriously when it gets cold out is when you'll notice this when the cable is dry. Yes kinked or burnt cable housings will make the cable "bind" and thus making the speedo jump. Do the external inspection like mentioned. If all looks ok take the cable loose at the trans and turn. If it doesn't bind then you can remove it from under the dash and try to get some light oil into the housing. Light machine oil is best. I believe the cable can only be removed from the housing from above. Correct me if I'm wrong. 9 times out of 10 it's a dry cable.
Like moparmark said, chattering and may I add squeeling will be the speedometer...

 

[71dodgechargerrt]

Thanks for the advice,I will try the cable first, may get one more cruise in and then park it till spring and dig into it further,

 

[Richard Cranium]

Check and lube your cable first

If my wife hadn't dried up, I wouldn't need lube.