Fluctuating Speedo

[basement]

This is on a manual 4-speed. Took the Challenger out for a drive after about 6mths in storage. Started up after about 20seconds and idled ok. Once it was warmed up I took it out for a quick trip around the block and noticed immediately that the speedometer was bouncing all over. Everything appears like its still connected ok. Where would the problem most likely be, at the tranny or the dash end? Or maybe I just need to take the car out and get it upto 120mph to blow the cobwebs out.

[MEK-Dangerfield]

My first thought is the speedo-cable might need some lube. If not that, then your speedo might need it. Then the speedo gear in your tranny might be wearing down.

OK, I have cleared up NOTHING, but these are the usual suspects. I just hope it isn't the gearing in your speedo housing wearing down.

[Bullitt-]

  With Mike..... lube speedo cable...but that's how mine acted just before it broke.

[moparmaniac59]

Mine has been "slipping" for a while. Does OK up to about 60 then goes crazy!! So I guess I am in the same mess as Basement. Not to steal this thread, but what type lube should be used on the speedo cable??


                                               Matt B.

[Bullitt-]

Mine has been "slipping" for a while. Does OK up to about 60 then goes crazy!! So I guess I am in the same mess as Basement. Not to steal this thread, but what type lube should be used on the speedo cable??


                                               Matt B.

White Lithium should to the trick.... 1-Drop of Light oil if you lube the speedo

[Aussie Challenger]

  Speedo cables have been known to draw transmission oil up the cable over time and get into the speedo head, when it mixes with the dust from many years it can clog up the speedo. Since this vehicle has been sitting for a while this may have happened.
  I have used light grease in the cable if it is dry, I don't like oil only because you have to use more than a few drops and that oil will end up in the speedo head. I have used a drop of sewing machine oil in the speedo head but now prefer to use a silicone spray.   

[resq302]

I had the same problem with a jumping speedo needle in my charger.  Ended up replacing the cable with a correct length one and the problem went away.

[basement]

Am i going to end up with a face fool of gear lube if I remove the speedo cable from the tranny end?

[73Chally]

I had a similar problem with mine.  Fortunately for me (I guess), it had some other problems so I had to send it in for repair anyways, and when it came back everything worked great, so for me it was something in the speedo itself, and not the cable.

[73EStroker]

the speedo cable making the needle wobbly is the most common cause of speedo needle breaking. If the cable is original then replace it with a new one. You will  and  if you have to repair the speedo because of this. I put a brand new one in cause I don't want to be fixing this car for a long time after a ground up restoration.