scorpion18z

I was just talking with John Dvorski of Redline today. I am having my speedometer upgraded to 140 mph and the tachometer resurfaced. John passed on some important information with regards to servicing the speedometer and tachometer cables. DO NOT GREASE THE CABLES. John advised me, contrary to some of the comments I have read on this Forum, that the spun wire inside the cable sheath acts like a screw as it turns. Over time this screw action pushes the grease/oil towards the heads of the speedometer and/or tachometer mechanisms, fouling them to a point where they may (and in most cases… do) cause problems with operation of the instruments. The buildup of oil and grease cause a mess that attacks dirt and grime. These cables did not come from the factory with any lubricants. They are dry for a purpose, one of which is so they do not stick to the casing. So when you take those cables out and service them just wipe them clean and reassemble. If you are replacing with after-market cables you will notice a smooth action and no lubricants. Comments are welcome.

MrJlr

Ya know...I never thought of that....I could see that happening though...

I simply replaced mine...brand new - no grease.

zwede

Sounds logical to me. I've never greased or oiled mine and it works perfectly.

Easy Mike

I've always heard to use graphite to lube them.

Paul L

Graphite lube does work well. Remove the inner cable and coat it. When the carrier (typically kerosene) is completely evaporated re-install the inner cable into the outer sheath. The now dry graphite (basically soft carbon) is an excellent lubricant and will not create a greasy mess that finds its way into the head unit.

doorgunner

AAAAAAAAAAAAhaaaa.....the flex-cable is coming back out.....

getting degreased....

and then graphited (it was binding--so I greased it to keep the needle from bouncing)

Thanks for the info......and for sparing me from having to disassemble the head in a couple years.

Vettereturned

Mine is making a little 'noise' according to the wife (I can't hear it). I was going to remove and lube it - but not now. If the cable snaps it'll get replaced.
Thanks for the tip.

gcusmano74

If the tach/speedo needle is bouncing, the cable most likely has a kink in it, and needs a new one.

Paul L

A mechanical tach bounching 25rpm at idle is normal. Once up to speed it should be steady.

billcarson

finally a thread i can sink my teeth into.

Lakeside49

Could be - but, they ought to state that their advice goes against the guidance of the cable manufacturers (they go to the cost, effort and hazmat regulatory brain damage to include a dab of lube with their new cables for valid reasons); and, my '82's GM shop manual specifies (pg. 8C-8) to always use GM speedo cable lubrication, and gives part # ST700. Bottom line, except for brakes, friction is usually a bad thing and the design engineers knew what they were doing. I use lithium grease on my speedo cables, and without any issues to date.

CaseyJones

Per the advice given a few months ago, I just did my cables. The cruise servo to transmission cable assembly was replaced and the cable given a light white lithium greasing while it was out. The servo to speedometer cable was then determined to be the cause of the needle bounce so I pulled it out and found a couple of clumps of crusty, rusty-looking grease on it. After a good cleaning and light lubing it was re-installing all is good. I was going to replace the whole thing but the aftermarket replacement was about four inches longer than the original (it was labeled as a tach drive or speedometer replacement).

WESCH

Hi

Mine was bouncing years ago, greased the cable with dry silicone grease and it was OK for many years until last summer. Made some noise and needle occasionally bouncing. I replaced the cable this time by a so called original 68 replacement unit, but the new cable also was longer. I could fit it, but not as perfect as the old one was.

Aftermarket stuff , pfff.

Rgds. Günther

loup68

I agree with EasyMike, I was always told to use graphite. The tubes even say for speedometer use. Lou.

calif phil

I have a tool that uses compressed air and a drill to lube speedo cables. I have had it for years. It came with AC Delco speedo cable grease.

jcloving

Yeah, I've heard this too.

I did need to recently lube my reverse lockout cable though. A bit of white lithium grease on each end and it works again.

Dustup7T2

To each their own but this is the product that serves my needs well.

v2racing

I can see the logic, but I've been greasing speedometer cables for over 40 years and never ended up with a speedometer full of grease or any failures from it.

doorgunner

Now that I think back, I was baffled once and did have one vehicle that I owned for 18 years that had a huge build-up of grease in the speedometer housing...the inner flex-cable must have been turning the "correct way" to cause the grease to collect....other than that, I've never had problems with grease.

CanadaGrant

I always use a drop of assembly lube on the end of the cable where it enters the distributor drive and that's it. I also have the distributor "clocked" about 45 degrees or one cylinder over so it's a straight shot from the tach drive to the grommet in the firewall instead of a 45 degree bend in the cable.