Tachometer Drive Cable Lubrication

[Bob_Roller]

I'm going to replace the ignition switch on my Lario this afternoon,went bad on me two weeks ago .

I had the instrument cluster opened up about 5 weeks ago, for an inoperative low oil pressure light .

While I was there, I removed the tachometer (mechanical tach) and speedometer drive cables, you can remove the cables from the outer conduit .

Cleaned and lubed them with a light air tool oil .

I would personally rather use a light grease than oil .

The only other bike I had with a mechanical tach, a '79 Yamaha XS400, I was told not to use grease on the drive cable, due to  the possibility of it working it's way up the cable into the indicator .

Is this a generally known fact, or just merely fiction

Haven't given it much thought for the last 32 years, since I got the '81 R65 .

[Luca]

Haven't heard one way or the other, but perhaps the wire wrapping on the cable can work as a screw pump on the grease if it spins the right way...  but usually the cable receptacles in the gauges are constructed tightly.  My concern would be putting excessive drag on the cable with grease.

Any particular reason you would rather use grease?  Longevity?

[Bob_Roller]

Oil just runs down the cable and leaks out at the bottom fittings .

Wanted something to stay in place .

Found some moly assembly paste at work, got a small container of it, going to try it the next time I have to remove the instrument cluster, or cooler weather, whichever comes first !!!!!!!!!!!!

The tachometer is fine, the speedometer needle is 'nervous', so it needs something else .

[Barry]

Grease would cause some drag and that may or may not be appropriate for this cable. I've seen cases though where grease was a good thing because the drag provided enough damping effect to eliminate needle flutter.

[Bob_Roller]

This assembly lube has a volatile component to it, after about a month  or two of being out of it's container, it's more like a dry lube than a grease .

Of course, I didn't think of using this, until the day after I replaced the ignition switch .

Too bad the switch I used, won't work on an airhead bike, the switch snaps into the detents much more positively than any switch I've had on a bike before .

The threaded portion of the cylinder is only 10 mm long, no where near long enough for an R65, barely long enough to work on the Lario .

[tvrla]

I'd think a light weight grease would be just fine. In the old days (I can say that now having lived through them  :-) we used to grease car and truck speedo cables with wheel bearing grease, if I recall correctly. I would use a synthetic grease because it wouldn't stiffen as much in the cold as the regular stuff.

As for it migrating into the tach or speedo - not too likely! The input shaft of the instrument rides in a bushing and there isn't much room for the grease to migrate through. The input shaft on the airheads is at least a couple inches long, so you can discount that as a problem!

[Bob_Roller]

Thanks wirespokes !

I might try a pressure greasing of an airhead speedometer drive cable with this moly assembly lube, when when I'm on vacation in Oct/Nov when I perform my annual maintenance on the bikes .

Too hot now to even think about doing it !!

[nhmaf]

I recall greasing speedometer cables on cars and trucks - I would also think that a light (not super-goopy or sticky) grease would be acceptable for your application.  As long as the outer sheathing wasn't packed solid with the stuff, I don't think that it would "pump" into the instrument