Tach needle wobble fixed!

[Bonz]

Ok, here's to announce I successfully fixed the tach needle wobble on my 80 SG.

It took some doing, to actually get the tach body out of the shell (had to uncrimp the metal ring holding the lens in place to pull the tach out of the shell) but once out, it was easy to put a shot of graphite spray lube in the front where the shaft is that spins the tach needle, and also put a shot of lube into the back of the tach "motor" housing thru the open spots on either side of the large wire end connector that is mounted there.

I think what I did takes the tech tip a step further, as by taking it apart this far eliminates the possibility of getting any lube on the circuit board since that is mounted externally to the tach "motor" body itself. You will see what I mean if you ever do this...

No wobble at any rpm, stable and steady now on the needle.

Only caveat is that I wish I could get the metal lens retaining ring crimped back as neatly as it was from the factory 31 years ago, but a properly working tach was worth it. I just took a wrap of black electrical tape around where the tach meets the rubber cushion that fits in the lip of the shell, and it looks pretty good.

Hope this is encouraging to the rest of you that may have a tach needle wobble. FWIW, I chose graphite spray lube like you would use to lube locks. Figured it was at least as good a lubricant as silicon if not better, and a dry graphite coating that is left behind would tend to be less insulating than a silicon coating if there was to be any issue of getting hot inside the tach "motor". I did this two days ago, so we'll see how long, if ever, it takes for the wobble to return.

[natemoen]

My only thought, which may not even matter cause I dont know what is going on inside the tach on these things, is that graphite is conductive and depending on how things in the tach work (again I dont know how these tachs work cause I have not been in one) and where the graphite gets it could cause shorts in the electronics. Where as the silicone is non conductive and would insulate from shorts.

Again I will add my disclaimer as to not get ripped a new one. I do not know the internals of the tach. There may not even be any open contact points where this would be an issue, so take this with a grain of salt.

Congrats on getting rid of the wobble!

[Bonz]

I hear what you are saying, I hadn't thought of that. By doing it the way I did, I would say I am safe as it is inside the tach "motor" housing and away from the circuit boards. I put "motor" in " " because that's the best term I can think for it, maybe there is a more correct term for what I am describing.

BUT with that said, anyone trying to spray inside the tach shell (the housing for the instrument/fuel/neutral/hi beam bulbs) as in the tech tip with the graphite spray WILL risk covering the circuit boards with it, so silicone in that case would be best.

GOOD POINT.

[DeanR]

I have the wobble at times and never realized that it was a lube issue. Might get in there over the winter.

[lvrsnr]

instead of deforming the metal ring to get in. you can cut the gauges case around the circumference with and pipe cutter or dremel saw bit mounted in a drill press then epoxy the two halves back together, it works great I just fixed a erratic speedometer this way... remember that before cutting put an index line on the side of the gauge case to help align the halves when reassembling.

[Bonz]

That could work well. I didn't think of halving the whole body... In the end, it worked out pretty well uncrimping the ring, but it didn't look as good once put back together, obviously, so I used an inconspicuous wrap of electrical tape around things to make it look pretty good. Since the tach body shell is not visible once put back on the bike, your method would be one I'd try next time.