Hello all,

So I recently rebuilt my C4 transmission and reassembled everything. Good news...everything seems to be working fine. The thing is that the speedometer, while it works, seems to bounce back and forth while it goes up and down. The cable seems to be installed snug and I tightened the bolt. Any suggestions on why this is happening?

 

Periodically it doesn't hurt to lubricate the cable.

Usually I just disconnect the cable from the back of the speedo and drip some decent oil down the cable. Usually I use something like 3 in 1 or a light synthetic.

Maybe a better way is to use one of those cable lube adapters that the motorcycle guys use. It is a block of metal that fits over one end of the cable and has a hole for the little plastic tube that comes with motorcycle spray lube(usually for chains). You just plug the adapter over the end of the cable and put the plastic tube in the adapter and give it a decent long squirt. The pressure from the spray can forces the lube all the way to the other end of the cable. Works very nice on a moto, but I never tried it on my cars. I got mine back in the 80s but assume they still sell these adapters.

Alternatively the speedo maybe getting sticky and may need a shop to take a look. But, if you are mechanically handy, you MIGHT be able to to clean and lube it yourself. It was pretty easy on my old cars in the 70s/80s. I am not sure if it is legal since it would be easy to set back the old style mechanical odometers. Don't know what kind your truck has other than it sounds like the speedo at least is cable driven.

Good Luck,

Jim Henderson

 

X2 on lubing the speedo cable. Mine bounced for years and I finally got tired of it, pulled the cable out and sprayed white lithium grease into the sleeve that the cable itself goes into, and put it back together. No more bouncing.

 

Thanks guys, I will give it a try. If I am just using lithium grease, any tricks to getting it as far as possible down the cable sleeve?

 

If you got a spray can of lithium grease with one of those plastic tubes... try my motorcycle adapter idea. I forget now what it cost, probably $10 30 years ago, so ??? I use it now on anything with a cable, but it doesn't get much use, so up to you if it is worth it.

BUT FIRST check the ends of the cable to make sure they are like motorcycle cables, no fancy stuff. Other wise the adapter won't fit.

Alternatively... SOME cables will slide out of the sheath quite a bit. You might carefully see if yours will pull out, BUT NOT ALL THE WAY, or you will have fun getting it back in. Then grease it and shove it back in.

Good Luck,

Jim Henderson

 

rethinking my last response a bit. I am not so sure the speedo cable can pull out much since usually there is a gear or stub at each end of the cable.

So, 79F150 can fill us in that would be great. This is probably why I always just used liquid oils from the top and let it work it's way down the cable over time.

Good Luck,

Jim Henderson

 

I did remove the cable completely from the outer jacket, but I also disconnected it from the trans end to eliminate another bend. I removed the inst. cluster so I had good access to speedo cable and then pulled it out, lubed it and slid it back into the jacket.There is a small , what appears to be a nylon bushing at the bottom end of the jacket, just turn the cable a little as you push it back in and it will find its way through. And yes there is a gear on the trans end so remove the C-clip and pull it off. Or.....pull it out from the bottom then you wont have to fiddle with taking the speedo gear off. Procedure should be pretty much the same as if you did it from the top.

 

I would use graphite oil and not lithium.

-Joseph