Speedometer fluctuating
Thread Starter
Intermediate
Joined: Nov 2017
Posts: 29
Likes: 3
Speedometer fluctuating
The speedometer on my 1963 C2 fluctuates at about 25 mph and I hear a "rattle" at the same from behind the dash board. Since the car has 68K+ miles on it the speedometer, cable, and the drive gear may need to be replaced. I haven't raised the car yet but when I get under it I'd like to replace the speedometer driven gear, drive gear fitting and other associated parts while I'm under it. My question is, can the previously mentioned parts be removed and replaced from outside of the transmission? Is there a "best source" for those parts? I don't mind the cost as I just received a NOS ignition switch for the car that ran $288. I originally replaced the burned switch with an American made after market one that said Mexico on the prong side??? Thanks for any responses.
Race Director
Joined: Nov 2003
Posts: 10,696
Likes: 3,094
From: Cottonwood AZ
C1 of Year Finalist (performance mods) 2019
Unless your speedometer head I bad (needs to be sent out for repair you should find all you need below.
https://www.corvettecentral.com/sear...=1963&count=36
https://www.corvettecentral.com/sear...=1963&count=36
Race Director
Joined: Oct 2005
Posts: 12,470
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From: Camp Verde AZ
C1 of Year Finalist (performance mods) 2019
2017 C1 of Year Finalist
The drive gear cannot be replaced with the transmission in the car. Only the driven gear. if you have rattle and fluc, its either the cable, or more likely the speedo head that is the problem.
Doug
Doug
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Joined: Jan 2002
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From: Close to DC
C2 of the Year Finalist - Modified 2020
Try the basics. Remove the cable, clean it and the casing all the way through. You may be surprised at the trash/debris that collects inside the housing. Take a stiff length of small wire, bend the tip over and pinch a piece of cloth in it. Soak the cloth in some cleaner fluid. Work it in and out until it's relatively clean. Get some "Cable Ease" and lube the cable no closer to the head end than 6-8 inches. I hope this helps, it did the job for me. 
Dennis
Dennis
Thread Starter
Intermediate
Joined: Nov 2017
Posts: 29
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Thanks guys, admittedly I'm a parts changer and not much as a diagnostic expert so all of your suggestions are a great deal of help. My parents gave me this coupe four years ago. It sat in their garage unused for thirty years so being able to replace any part that holds liquid has saved me lots of money. Having owned, worked on, and relied?? on English sports cars during my early years affords me plenty of knuckle busting experience. The only issue is the fact that I'm 72 now and am not as flexible as I used to be.
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Team Owner
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Army
All of the above BUT, my 63 speedo was bouncing at odd times and I initially thought it was when I was going over a bump....then I figured out that the odometer/trip meter affect the gauge so I made a bracket to hold the trip meter in permanent reset and reduced the gear train load by half. No more bounce.....
This prob wouldn't help if your setup is too far gone but it fixed me up...
Last edited by Frankie the Fink; Dec 15, 2018 at 06:40 AM.
Thread Starter
Intermediate
Joined: Nov 2017
Posts: 29
Likes: 3
Thanks for the suggestion Frankie. I just had all of the original suspension components replaced including the leaking steering box and rear wheel bearings. I reset the trip odometer to track mileage after the work and the plastic **** disintegrated. I probably should have secured the stem with needle nose plyers when I pushed the new one in place. I'll test what might be your solution to the jumpy needle as I drive. Certainly easier than removing the speedometer. However that would be accomplished