rich5962

I posted this on the NCRS site and wanted to share this here as well.

Below is clear evidence of what happens when speedometer or tachometer cables are over lubricated or lubricated with improper materials.

I received this 1967 cluster from a friend. He said the speedometer gets stuck at various speeds and won't return to zero. It's a speed minder speedometer so I thought that function was possibly jammed. I had never worked on a speed minder unit before so I was uncertain what to expect, as well as parts availability.

What I found was a totally grease encased speedometer cup and gearbox. Because the grease was so thick and aged, it lightly jammed up the rotating needle shaft cup and magnetic main shaft.

I am convinced this was caused by cable overlubrication over time, and likely using a chassis grease or possibly even a grease gun at the transmission end of the speedo cable by a prior owner or technician. I've never seen one this bad.

Proof of what happens if the cable is lubricated improperly. It took me about a hour to dissassemble and using my parts washer, spray cleaners, brushes, q-tips and various pick tools, to clean all of the grease and embedded dirt away from everthing, and then reassemble and test the speedometer. The grease was so thick and gooey it took a fine wire brush to clean it out of the gear teeth.

After cleanig and reassembly the unit worked flawlessly. I even learned how to fix the speed minder function that wasn't working properly. Interesting little mechanism that is.

Lubricate cables wisely. Use a light lubricant specifically made for these cable systems. Never use grease.

Rich

DansYellow66

You're a braver man than I am to tackle one of those. Cable graphite lubricant is hard to find these days but it is still out there to be found with some effort. Thanks for posting.

1snake

I was told by my local speedo repair shop to use a thin coat of Vaseline on the cable and nothing else. I've used it on several cars with no problems. Another issue is the speedo. drive that goes into the trans. In 66, a seal was added to keep trans. fluid from moving up the cable to the speedo head. Here's a pic. of what can happen when using a speedo. drive prior to 66 without the seal. Notice the gear oil in the cable and on the Z bar.

TheSaint

I have not lubricated the speedo or tacho cable on my car so i guess it is time to do it next summer

I was planning on putting on at the transmission side of the speedo and distrubitor side of the tacho using some white grease i do not remember what that grease i called

abe g

After 50 years of ownership (and one cable replacement) I found that a few drops of engine oil were all that was needed to keep things running.Regards, AbeG

abdo

Some advice I received from others is to not lubricate the cable drive at the speedometer end. Leave about a foot of cable without grease. There is less tendency for grease to enter the speedometer.

JohnZ

Corvette Central sells "Kable-Ease", which is a graphite emulsion in a light carrier made specifically for lubrication of flexible speedo/tach shafts. I bought this tube many years ago, and it's a lifetime supply.

Pilot Dan

SYL-Glide available at NAPA is what I use. Great stuff with many uses! You don't want to lubricate the last 12 inches or so of the cable at the Speedo head (or Tach) because the lube will migrate up on it's own. Pilot Dan

rich5962

Since I don't have the car here, only the cluster.....

Is it possible the grease I found on this speedometer is from the transmission lube?

It didn't have that nasty aroma like 90W oil so I figured it wasn't from that. All I can think of is a grease gun pumping black wheel bearing grease into the other end of the cable.

Either way, I need to tell my friend to remove his speedo cable from the car, remove the inner drive cable, then clean both in a solvent cabinet. I wonder if he'll be able to get it all out of the cable housing.

Rich
p.s. That Kable-Ease looks like the right stuff.

1snake

Your pics. clearly show that it's chassis lube. Somewhere I saw an adapter that you can put on your cable end and pump it full using a grease gun. Always thought it was a bad idea.

rich5962

Jim, After looking at your pic above and seeing the color of that cable mess and what was on the z-bar, it certainly looks different from what I saw on this one. It sure seems like somebody pumped this one full of grease. I've sent the pictures to my friend so he can see what was in there and I'm curious what he finds in the cable itself.

In the past I've used a CRC product called Power Lube.


It's made for many things including speedometer cables. It's a light slightly foaming spray that leaves minimal residue. I remove the cable from the housing and lightly spray it on the entire length and let any excess run off the end. I've never had a problem using it for cables.

What I also really like is that it's a low pressure spray that comes out very slowly, unlike that messy high pressure jet spray like WD-40.

Rich