Speedometer not working

[Vortech]

My speedometer was not working so I disconnected from back of panel assembly to see if inside wold spin while If drove it. It was not spinning, I fiddled with it while driving and got it to work for a second. The transmission is a 3 speed with OD. The attached picture shows the cable ends. The red end plastic tipped was in the cab. The other end was in the transmission. Is this the correct orientation. What could be the problem?

[Ozzy2013]

Wow good question all the cables i ever messed with the bare square end went to the speedo .If you can spin the cable by hand when its hooked up to the trans its broken .

[Crazy Rusty]

Just had this in mine. cable was broken about half way down and would sometimes catch and half-work. pretty easy test/fix just to replace it and only costs like $4 at autozone.

[65chevysub]

Sorry to break in on this thread, but I'm having issues with my speedometer as well. It works, but at lower speeds, it bounces back and forth above and below the speed I'm driving. My trans is a 1978 TH350. I replaced the cable probably 15 years ago or so, from Autozone, but it's for a Powerglide, not sure if that makes a difference. Started doing the "bouncing" awhile ago, not recently. Could my cable be getting ready to quit on me?

[Mike Wessinger]

When mine started bouncing I pulled it, cleaned it, then lubed it before I put it back in. Seems to have taken care of the problem.

[63burban]

Originally Posted by 65chevysub

Sorry to break in on this thread, but I'm having issues with my speedometer as well. It works, but at lower speeds, it bounces back and forth above and below the speed I'm driving. My trans is a 1978 TH350. I replaced the cable probably 15 years ago or so, from Autozone, but it's for a Powerglide, not sure if that makes a difference. Started doing the "bouncing" awhile ago, not recently. Could my cable be getting ready to quit on me?

Speedometer itself needs to be cleaned and re lubed. The original lubrication dries up after all these years and just needs a little lovin.

[65chevysub]

Thanks Mike W, and 63burban. Will 3-N-1 oil work for the speedometer, and the cable? Is there a thread on cleaning the speedo? I wiped mine down a few months ago, and it took some of the paint off of one of the numbers on the odometer, without using any cleaner. I'll eventually get a decal set for it, but right now I'll just clean and oil it.

[Vortech]

Cable looks good. How does it attach at the trans. I pulled the adapter on the trans housing in order to replace leaking o ring. Saw a cylinder inside. Could the cylinder be removed to inspect without messing up trans?
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[akqj9]

I have heard of lubing with the wrong oil and having the oil work its way up the cable and splash on the inside of the speedo dial. I took my cable out, cleaned the housing and cable then wiped grease in the cable.

[1963c-10]

Talking about the speedo trans gear? It will just slid out and then you can replace the o ring.

You can see how it gets locked in by the little plate with the bolt behind it.

And I like graphite based lube for the speedo cable. Works far better than wd40.

Clean the cable inside and out as best you can with carb cleaner or something similar. Soak it in a bucket if you have too. The nice thing about the graphite is it won't eventually gunk up on you and it doesn't get temperamental under hi or low temps.

[Vortech]

Ok, I pulled that but there was a separate tapered cylinder inside loose. Maybe the trans gear is broke?
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[1963c-10]

I have a 3 speed parts diagram....maybe it'll help.

PM me your address and I can send it to you.

[Vortech]

Thanks, I think my gear is missing or broken. Where can I source these? Need the white gear at the trans

[wbc409]

Make sure you identify the color of the speedo drive gear in the trans. Different colors have different gear tooth counts