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noisy tach on a 84 vt500

11K views 19 replies 12 participants last post by  Onehit 
#1 ·
Hi everyone,
with the colder weather my tach has started to show its older age, it has a whining/ grinding type noise that changes with engine speed, same type of noise as a speedo will make when it starts too seize up or get dry. Now I did earlier this summer tear apart my speedo and clean and lube it and it is doing great but that is not a easy job to get back together properly as they I do not think were ever meant to be taken apart.
Does anyone have any suggestions on how I can fix this, or is disassembly the only way? Earlier in the year I did try to spray a little grease just in the end cause it was slightly noisy then but then I guess the oil was too heavy cause the tach became somewhat non responsive, it would move but would return very slowly, but came back to life after a few rides.
 
#2 ·
I would try to blow it out with some electrical contact cleaner first, that hopefully will flush out any crap and lube that is too thick.
I don't know if this will work, but...you can get dry lube in a spray can, spray in the tach and when it dries, it leaves only a dry lubricant film. The Home Depot has one that has mica in it. I am sure you can get graphite based lubes too. Someone else help here, don't know if any of these conducts electricity and would hurt or not? Also, if you have cable driven tach, not electonic, you may want to lube the cable.
Dan
 
#3 ·
It is a mechanical tach and the only electrics is the bulb. The cable is/was greased plenty with white lithium, what I had at the time. This morning after posting it was barking at me...it would whine and then not then really whine and vibrate and then not. I smacked it and it would change pitch but still did it's thing. I can hear it over my Mac pipes at 5 grand, I laughed and said I need to fix that, I can imagine what that sounds like from the side of the road, luckily when I get out of work it is warmer and it does not make noise then, earlier in the morning there is no one around anyhow.
But seriously I am afraid to spray too much of the wrong thing up in there but if I do I guess I could always rip it apart and clean it up. I am just hoping with a bike this old that someone has dealt with this problem before.
 
#4 ·
I have the same issues with my tach and speedo (83 vt500c) I have considered taking them both apart to clean and lube them, but been unsure if it was a wise thing to do or just find new ones on ebay. I'll be following the thread to see what results that you get.
 
#5 ·
I have already taken apart the speedo and cleaned and lubed and it works great now, it was very noisy, screeching. I used a dremel to split the casing around the bezel and slowly bent it back to remove the glass and gasket and the rest was easy until it was time to put back together. I very carefully folded the metal back over and really tried to make it unnoticeable but did not entirely succeed but unless you knew it was done you probably would not notice it. So it can be done, plus one of the screws for the face was laying in the bottom of the speedo anyhow. Just take your time.
 
#6 ·
I remembered that I had some graphite in a spray can that is the dry kind and I went ahead and tried spraying some up inside and it has not made a noise since, I got more on me and the bike than I think went inside but that was ok. So this does work so far.
Thanks all for the suggestions
 
#7 ·
When my speedometers whined, I removed them, turned them upside down and sprayed WD40 in them. I had liquid WD40 in them and when I set them upright and allowed the excess to drain out, they worked well and there was just a minor oily look to the faceplates. Much better than the whine!

I sold those bikes so I don't know how long the fix lasted.

ride safely,
 
#9 ·
Having this same problem with the tach on my 83 vt500c. I can literally hold it forward torward the headlight while it's buzzing and it'll quiet down. I'm curious as to what exactly you guys are lubicating here? As annoying as the sound is im sure I'll have it fixed or a new one ordered by the time I get a response, but all is appreciated!



~Ride On Homie~
 
#11 ·
I am having the same issue. 83 vt500. Bought 2 used ones, same issue. Replaced the tach cable with a new one. Same problem. Slapping tne side quiets out down for 20 sec. Then back again. I will try the graphite. Do i Spray into the hole where the tach cable would be?
 
#12 ·
That is what I did, seems to work for awhile but not forever, I ended up disconnecting mine during the winter months, was riding in 30 degree weather and the tach was screaming!!
It seems that Ramie posted a rebuild of tachs link but it was for the vt700/750 electronic tachometers, dealing with a faulty mount?? anyhow the fact that we all know we can reach down while it is screaming and move the tach and make it stop is curious, maybe Ramie is onto something here, cause I have thought about jamming something to hold it into place but never did believing that the problem really must be a worn out bushing or the like, but maybe it is just misalignment??
But right now I have more pressing problems...leaking forks
hopefully the graphite works for awhile it did for me
 
#13 ·
I have the same issue for my VT500c, and like others, only in cooler weather. I'm just unsure if it is my speedo or tach making noise. The noise is distracting, even with earplugs. I did remove and grease my speedo cable with silicone grease in early Spring, so not cold enough to know if it will work when cooler. It did stop the squealing, but then again maybe it was the higher temperatures.

I searched the VT500 Yahoo group and came up with this single post, but no real solution.
 
#14 ·
As the cable wears inside the housing it can have more play and whip around inside and certain RPMs. Maybe try to bend the cable run a little with a cable tie to pull it off center enough to help the slack inside. Just a thought.
 
#16 ·
Speedo AND tach doing this

Just went for a long ride (in the rain) on my wife's '84 Shadow 500. Over the course of many miles, a noise began to grow in what I THOUGHT was the water pump - but it was coming from the instrument "panel." Then, both the speedo AND the tach began wildly jumping around, and the noise got much, much worse. Going around corners, things would quiet a littl. The whirring/buzzing noise is really, really loud - sounds like gears not meshing properly (or a water pump bearing in imminent failure). Engine's running fine, temp is good, but the noise is incredible. Worse, though, is the fact the speedo and tach are now more or less useless. Noise persists at a reduced level even when sitting still/at idle. I know these cables are not actually connected together, but they're acting as if they are - and as if they share a common problem. Checked connections when I got home, wiggled cables, etc. but find nothing obvious. The fact it's BOTH gauges acting up has me most confused.
 
#17 ·
Since they are 2 separate systems and cables, it is weird that both are effected. But If the tach cable is causing a vibration and the whole instrument cluster is bolted together it could induce the vibration into the speedo needle. If you disconnect the tach cable from the top of the cylinder head it may stop all noises and you can diagnose it from there. After that grease the tach cable. Then pull the tach and put some oil or graphite in the back of the tach drive. Not too much, and work it in and see it it helps.
 
#18 ·
And I've also experienced this on my '83. A good slap gets it to stop, but the next time I apply throttle, the tach whines loud as hell.

While it's not an essential thing to operate the bike, when we start getting snow and Ice on the roads here in Atlanta, I'll garage it and pull the tach apart, and document my findings.
 
#19 ·
As others have found it seems to be in the tach head not the cable. So if you pull it off the bike and turn it up side down and put some light oil maybe with graphite mixed in, in the rear of the cable housing it will get into the bushing area and lube it. Not too much or you will have it on the face of the tach inside. Spin it with a small screwdriver to get in the bushing.
 
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