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Jumping Speedometer

JimKueneman

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Sonoita, Az
Well as with any old car that has not been on the road in 35+ years this weekend I am working the bugs out. The speedo is very jumpy and getting worse. I had the dash out and I cleaned and lubed the cable during the restoration. I pulled the cable up and ran it very straight with a drill on it and it still jumps from rail to rail. I can hear a "tinny" coming from the cluster that is in sync with the speed of the cable. I am assuming it is the 2 shells where the magnets are touching each other (bushing or something). Thoughts on how hard this to fix? I disconnected it so I don't damage it more than it is.
 
Maybe if you disconnect the cable from cluster and it stops it's the speedo. If it's still there disconnect the cable from trans without re connecting cable to cluster, why bother reconnecting it. If no noise after removing from trans it's the cable.
 
Maybe if you disconnect the cable from cluster and it stops it's the speedo. If it's still there disconnect the cable from trans without re connecting cable to cluster, why bother reconnecting it. If no noise after removing from trans it's the cable.
do you have the correct trans speedometer gear ratio for rear tire size.
 
Maybe if you disconnect the cable from cluster and it stops it's the speedo. If it's still there disconnect the cable from trans without re connecting cable to cluster, why bother reconnecting it. If no noise after removing from trans it's the cable.

It makes no noise with it disconnected. I am leaning toward the speedo. I has 88k on it and was in storage (inside) since '84.
 
One other thought is the gear in trans properly engaged?
 
Have you seen the Commercial, "It's what they do. Mine has a little bounce, but no noise. Lubed, aligned etc. Use the Garmin for ground speed.
 
One other thought is the gear in trans properly engaged?

I did have to rotate it to the lowest gear setting (the transmission shop put it in the center setting but I have 2.94 gears so I have a 28-30 tooth gear). It did not work at all on the first drive.
 
Have you seen the Commercial, "It's what they do. Mine has a little bounce, but no noise. Lubed, aligned etc. Use the Garmin for ground speed.

Mine bounces from 0 to 120Mph, it is useless and is smacking against the end stops hard.
 
When I get some ambition I will jack up the rear and run it in gear and see if the cable rotates smoothly under the dash. I have been working out the bugs on the whole for the last day and a half, I am done for a while.
 
If there's no noise with cable dis connected I'd lean to speedo but who wants to pull the cluster, so I guess a test of cable is wise move. All it takes is one wire in the cable to break.
 
what did you use to lube the cable? Did you remove the inside cable and clean it with varsol to get the junk off it, then lube it with graphite, rather then grease?
 
By grease you refuring to cable lube? You may also want to check the speedo gear install as the housing needs to be properly aligned in the case for proper tooth engagement.
 
what did you use to lube the cable? Did you remove the inside cable and clean it with varsol to get the junk off it, then lube it with graphite, rather then grease?
I've never tried it on a Speedo cable but I've had luck freeing up parking brake cables. I find a hose that can be clamped on the outside of the cable then attach an air fitting, fill the hose with automatic transmission fluid (high detergent and thin) then pressurize while spinning it with a drill on the other end. Worked for me, I'm still running 1969 brake cables and they work freely.
 
Speedo, if you spun the speedo with a drill and its going crazy it's the speedo.
 
Just pull the cable out of the housing and spray some carb or brake cleaner down the housing, lube and reinstall the cable and recheck operation.
 
Just pull the cable out of the housing and spray some carb or brake cleaner down the housing, lube and reinstall the cable and recheck operation.

I did all that when I restored the car. The cable works flawlessly. I am sure it is either the gear (though I would have expected the transmission shop to notice that) or the speedo. I will run it on jack stands and see how the cable spins the housing.
 
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