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Speedometer problems

6K views 8 replies 5 participants last post by  huntster 
#1 ·
I have a 69 GTO and the last several cold (40 to 50 degrees) days I took the car out the Speedometer made a scraping like noise and the needle was bouncing around like crazy. It would go from 40 to 120 mph and back and forth. AFter stopping for breakfast the car sat in the sun and when I started it and drove on to the road the Speedo seem to work fine except for an occasional back and forth jumping. The scrapping noise also stopped or at least diminished quite a bit. I figure it is in the cable, maybe needs to be changed or lubricated. Could it also be in the speedo casing itself?. Any comments would be appreciated. thanks Soups.
 
#3 ·
Sure. It's not a difficult fix at all. The cable does need to be lubricated. Disconnect the cable at the transmission end then pull the center cable all the way out of the sheath. Get yourself some of this stuff:

Dorman Champ 9-1812 - Speedometer Cable Lubricant | O'Reilly Auto Parts

Lube the cable up good, slide it back in (twist it as you're pushing in the last few inches to make sure you re-engage the speedometer), reconnect and you should be in good shape.

Bear
 
#4 ·
Thanks for the info. I will probably change the cable since I have no idea if it is the
original or not. They are not that expensive and pretty easy to install. I hope that is the problem. As you know if it is in the speedo head then that is a little more involved.
Soups
 
#5 ·
Of course you're free to do as you like, but in my experience the reproduction cables brand new are poor substitutes for even worn factory originals. If'n it were me, I'd at least try to lube the original. If the results aren't satisfactory then the other option is still there.

Bear
 
#6 ·
Sure. It's not a difficult fix at all. The cable does need to be lubricated. Disconnect the cable at the transmission end then pull the center cable all the way out of the sheath. Get yourself some of this stuff:

Dorman Champ 9-1812 - Speedometer Cable Lubricant | O'Reilly Auto Parts

Lube the cable up good, slide it back in (twist it as you're pushing in the last few inches to make sure you re-engage the speedometer), reconnect and you should be in good shape.

Bear
Bear, I'm having the same issues as Soups. Is there any special procedure for removing the cable? When you reinsert do you twist only a certain direction? I'm just concerning about breaking my speedometer, etc. When reinstalling the transmission side, does it just push in and tighten up a nut?
 
#8 ·
Be careful with graphite, at least the pure powder stuff. I tried to clean my origin Speedo cable and lube with graphite. I thought I thoroughly cleaned out all the old grease and dried it. I then sprinkled graphite on the inner cable and inserted it into the sheath. It worked great, but when I got it back out, the graphite had found moisture, probably old grease, and became like concrete. I couldn’t get it back out and it ended up ruining the cable
 
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