Speedometer jumps ahead and makes noises

[pops1969RR]

After I get up to speeds over 30mph, my speedometer startsmaking racket and the needle bounces back and forth to 20+/- mph faster than I'm going. The noise sounds like the speedo cable is slipping in the socket, or the speedometer gears are jumping track. It doesn't always start at 30mph, sometimes it doesn't happen until higher speeds, but it does it without fail everytime I drive it. If I slow down to about 10mph it quits, but then does it again after I get up to speed. I thought it might be the cable coming loose from the speedometer, but I've unplugged it and plugged it back in several times. The cable shaft still looks square and has good shape. Has anyone had this problem, and/or does anyone have ideas? The speedometer cable is cheap enough, I may just replace it to rule that out.

For the time being I've unplugged the cable so that I don't cause further damage...

My car info...69 RR 383, 4 speed, factory rearend/gear ratio.

 

[mac]

if you can pull the cable out of the housing and lube it up, that might take care of it. had an older car that had the same problem. old saying is a little lubrication is a good thing.

 

[69hemibeep]

I just put a new cable into one that jumps around and pegs beyond 120 when going about 20mph. I'm pretty sure the cluster is coming out of this one.

 

[Basketcase]

my truck does this every winter till I've gone a few miles. Fine in the warm weather. Pull the cable and check for condition, and if it needs lubed.

 

[moparmonk]

Your cable thought solved one of mine like that! Hope it does for you

 

[bigmanjbmopar]

x3 install new cable I have gone through 2 now, oem snapped at cluster, 2nd one trans guys moved it too close to headers and it melted.

 

[pops1969RR]

An update for those who might look back on this post in the future...

I disconnected the cable at the speedometer and at the tranny, pulled the steel cable out of the plastic sheath, sprayed a lot of WD-40 white lithium grease through the sheath, put it back together, and it works as it should now. :semi-twins:

 

[Basketcase]

 

[quikbird]

A little grease makes the world go round