Speedometer Drive

[Rikugun]

On a recent ride I encountered a strange noise that I believe (hope?) to be from the speedo drive area. More specifically, a dry bushing in the speedo unit where the cable attaches. QBC and others have posted techniques for lubricating this area. I haven't yet addressed this but was curious to see what exactly the parts looked like. Since I have a damaged speedo, I removed the parts in question to get a better look. The parts are pictured below with the cast aluminum housing on the left obviously being the outer component where the cable attaches. The "guts" of the drive is on the right.

From top to bottom the parts are: a magnet which influences the indicating needle, a gear for the odometer, a non-ferrous bushing, and at the end a brass bushing. The magnet, gear and bronze bushing spin as one inside the silver non-ferrous bushing and are driven by the cable inner. The silver colored bushing is a press fit inside the housing. The bronze bushing at the bottom spins inside the end of the aluminum housing and is where I'm guessing the offensive noise is generated when no lube is present.

I suppose the silver bushing could also be the culprit but the remedy of working grease into the end between the housing ID and bronze bush OD has me thinking that is where the problem lay. Given the tolerances of the parts it seems less likely that method of lubricating would get much under that silver bushing.

I'm not entirely sure why the bronze bushing is even included? Why couldn't the silver bushing just extend to the end of the housing? Maybe somebody has some ideas.

[The Prophet of Doom]

I've never had one of these apart, but I'd guess it's possibly a graphite impreganated bronze. These are lubrication free.
Generally meters don't have lube in them - it attracts dirt and so long term issues. Don't use moly grease unless you want to buy a new cluster in 6 months.

If it's this part that is squealing then I'd double check for the absence of foreign materials.  If you must lube, then a very little graphite lube (a small drop only), or better still a spray with some dry film lubricant.  I'd be looking at  the drive down by the wheel, and the cable as more likely and more easily addressed culprits.   

[QBS]

Rik, thank you for the disassembly.  I've never gone into a speedo head from the cable input end.  Good to know what we are dealing with.

[Rikugun]

I've never had one of these apart, but I'd guess it's possibly a graphite impreganated bronze. These are lubrication free. Generally meters don't have lube in them - it attracts dirt and so long term issues. Don't use moly grease unless you want to buy a new cluster in 6 months.

The drive at the wheel and cable are good. I'll be lubricating the bronze bushing that spins in the end of the housing as this seems to have worked for other ROV'ers. I doubt one could get lube much further than that. I assumed the silver bushing was a soft and/or self lubricating material. As far as the bronze bushing at the end is concerned, if it is self lubing - it apparently ran out. There are some minor scratches on the one pictured although that unit was quiet right up to the time the bike was crashed.

QBS - I thought you would enjoy seeing the parts!