Speedometer Questions

[Guest]

Along with my 83 GS1100G, I have a 96 Honda Rebel that had a speedometer crap out. Replaced it with new used Rebel speedometer. Now the replacement speedometer is crapping out too just like the first one. Making a whirling sound and reading a higher than actual speed and jumping around. I took the old speedometer apart last night and cleaned the inside out with brake part cleaner. Question, is the speed cup supposed to be attached to the shaft? and move up and down on the shaft? Seems like the cup should not move up and down (1/8") on the shaft. The movement causes uneven turning and rubbing on the cup side bracket. Btw, I replaced the cable, lubed it good, and replaced the speedometer gear unit on the front wheel.

Now the worst part is my tachometer on my 83 GS1100G is starting to make a whirling sound too.

Any help would be greatly appreciated...these things are driving me crazy!

[rustybronco]

If the needles on both are jumping wildly and there is no damage to either drive cables, then I suspect the dampening mechanism's on both gauges have gone bad.

[eil]

I've already had a couple of these go out on my 850 and it appears that the main culprit is the bearing where the cable connects to the tach/speedo. When this goes, it not only makes a godawful squealing sound, it eventually causes the magnet rotor thing to contact the speed cup which sends the needle full-scale and breaks it. That bearing is difficult to lube, but it can and should be done. (If it squeals, it may already be too late.)

And unfortunately since these are largely one unit, it's difficult to break them down and then reassemble. Some have done it, but once you get it apart, there are lots of little fiddly bits to deal with as well. The best bet is usually to source a low-mileage replacement on eBay or this forum.

Of course, this doesn't necessarily apply to your Rebel speedo which sounds like it could be a different issue entirely.

[NashGS83]

Got a Rebel Forum reply, he said that I shouldn't have lubed the top 6 inches of the cable because the lube can get into the speedometer where it doesn't belong. I lubed the top six inches of the new GS tachometer cable that I installed in December...is this causing the whirling noise?? Do I need to open up the tachometer and clean it out? Does the tachometer operate with an eddy current like the speedometer?

[eil]

I don't think that's true of the GS speedo. Unless the cable is literally filled with oil, gravity is going to make sure that not much gets past the housing bearing that the cable connects to. (Which does need some occasional lube anyway.)

The tach does use the same magnet and cup arrangement as the speedo. The tach can be taken apart, but they aren't really meant to be, so it's a little involved. And once you get it apart, all the mechanical bits are one assembly so there's not really much to do except inspect it, clean it, lube it. I think the procedure is up on basscliff's site.