Speedometer Problem-Help!

[Vette66AirCoupe]

A while back my speedometer cable started jumping all over the place while I was out cruising. It was making a scratchy sound and in less than a minute it just stopped. No more noise, no more bouncing. In fact I was cruising along a ZERO mph on an interstate. So i purchased a new cable and I'm just now getting around to replacing it. All was going well until I just couldn't seem to get the squared off end of the cable into the back of the speedometer. I never had so much trouble before so after quite enough time standing on my head I finally yelled uncle and climbed out. I thought I better look at the end of the old cable to see if I had a match. Well, I don't. The old cable has a red plastic end on it that looks like it may be less than complete. I'm afraid part of this piece has broken off inside the speedometer and that's why I couldn't get the cable to go in far enough for me to screw the restraining collar up on it. Has anybody ever seen this type of speedometer cable end? Does anyone have another theory? See photo.

 

[67HEAVEN]

Terry,

Are you talking about your C2 or C1? If C2, that doesn't look like any cable end I've seen.

 

[Vette66AirCoupe]

Sorry, I should have posted that.....it's the '66.

Terry

 

[allcoupedup]

The speedo and tach cables have a stamped square-off section at either end. The square section is what slips into the speedo head and the speedo gear at the trans. You cable has a round steel inner cable. The squared off part I'm talking about is made by placing the steel cable in a rectangular die and smashing it.

Was there a squared off plastic piece at the tip of the red cone? Can't really tell in the picture but it looks like something may have sheared off the tip of that red piece... probably a rectangular piece.

?????
Brian

 

[67HEAVEN]

Can you easily remove the plastic from the end of the cable?

 

[midyear]

This type of cable end is on most all aftermarket replacement cables, and I think most all GM's since the late 70's. The plastic end is designed to break when put in a bind, this will save the other components from being damaged. The most likely cause is a dry speedo head binding the cable. clean and lube the speedo head, the broken plastic part should remove easily, and replace the cable.


Dennis

 

[Vette66AirCoupe]

Allcoupedup - I believe there was a rectangular piece on the end of that plastic piece that has indeed sheared off.

67Heaven - I tried to pull the red plastic piece off and it won't budge even with pliers.

 

[Vette66AirCoupe]

Midyear - Sounds like I'm getting ready to learn how to remove an instrument cluster from what you're saying. I'm not looking forward to that!

 

[JohnZ]

Unfortunately, you'll find the broken-off small red square drive end inside the speedo head drive coupler :cry