Tachometer Noise

[93Bandit]

I went for a ride a few weeks ago on my 83 850L and on my way home I came to a stop at a stop sign and heard a whining type noise, very similar to the whining sound those cheap plastic windup toys make. The tach was reading the correct RPM's so I tapped the gauge and the noise went a way. Rev'ed the engine and the tach worked correctly and there was no noise. Later going down the road I heard the noise again, tapped the gauge and it went away. I assume this is likely an issue with the tach, not the cable?

I recently took my speedo off because the needle was erratic and was sticking. I tried to dissemble it to lube the inside, but it didn't seem to be very dissemble-friendly. I lubed it the best I could and it seems to work better now. But, it never made a noise like my tach is now. Should I use a similar approach on my tach?

 

[Rich82GS750TZ]

Going through the same thing currently on this thread. My noise was not the tach cable, but the speedometer cable. My noise stopped when the speedo gable finally broke.

 

[93Bandit]

Going through the same thing currently on this thread. My noise was not the tach cable, but the speedometer cable. My noise stopped when the speedo gable finally broke.

Interesting. Your cable was making that whining type noise? My speedo cable failed a few years ago but it never made a noise. Interesting.

 

[Rich82GS750TZ]

So, speedo cable removed. I figured I’d lube the tach cable with white lithium squirted up from the engine end without removing it at the tach end and go for a ride. Tach cable is now making an even louder whirrring noise than the speedo cable was. Got back home and removed the tach cable completely. Smelled like it was burning. Tabbed spindle coming out of the valve cover appears to be spinning fine. The oil seal and Oring there were replaced a year ago. I’ve taken the inner cable out of the outer and flushed it with brake cleaner, cleaned and lubed the cable and put it back together.

I have the tach off and plan to flush out the drive hole with brake cleaner later tonight. Maybe my previous work forced some gunk up in the tach. Wish I could learn to just leave stuff alone.

 

[93Bandit]

I went back through my service records, and I didn't replace the speedo cable a few years ago. I replaced the tach cable, but I don't recall what brand it was. I'm sure it was a cheapy... So maybe I need to take the cable off and clean and lube it. That would be easier than messing with the gauge.

 

[bwringer]

FWIW, OEM cables are WAAAYYYYYYYYY better quality than the aftermarket crap and come pre-lubed.

And they're usually close to the same price.




Where the cable attaches to the gauge, the coupling starts squealing when it gets dry. Remove the gauge and get some sort of lubricant into that coupling. There's a spinny bit in the middle with a square hole for the cable, so you'll need to get something onto the exterior of the spinny bit. Just take care that the lubricant can't drip into the gauge face and look nasty; don't hold it upside-down or flood it with spray.

I've had success with working in a few drops of gear oil or motor oil. There may be something better out there.

 

[93Bandit]

Thanks for the tip, bwringer!

I think I replaced the tach cable before I joined the forum so I likely purchased an aftermarket cable. I'll have to dig further into my records to see if I can find a receipt.

I'll pull the gauge and see what I can do. I successfully lubed the speedo so I should be able to do the tach the same way.