Bad vibes


Information and questions on GL1500 Goldwings (1988-2000)
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Sidcar
Posts: 742
Joined: Thu Jul 05, 2012 3:07 pm
Location: Birmingham, England, United Kingdom
Motorcycle: 1995 GL1500 SE (20th Anniversary) and Squire RX4 sidecar

Bad vibes

Post by Sidcar »



The alternator packed up on my 95 GL1500 SE.
I fitted a high output alternator which charged lustily and went off on a run with some friends but it was spoilt by a vibration which made the handlebars tingle.
Sods Law it was a long run of about 100 mls. When I got back I got a new set of damper rubbers and fitted them but it made no difference.
I then refitted the old alternator which made a real improvement but there was still vibes to be felt in the 'bars.
I tried refitting the old dampers bushes but no difference. While the alternator was off I tried to check the torque on the engine side alternator coupling.
The manual says to put the bike in gear, hold the back wheel and then tighten the nut to 58nm.
I put the bike in gear, the back wheel was on the floor so no need to hold it, but when I came to check the torque the coupling keeps going round and round. There is resistance but not enough to apply 58nm to the nut.
Should it do this, is so how are you supposed to undo/tighten the retaining nut, or has something broken inside the alternator drive gear which is now causing this vibration?
I don't know whether this has any bearing but about 2 years ago I pulled out to overtake a lorry going up a steep hill in the wet and when I whipped the throttle open instead of accelerating the back wheel spun causing the engine revs to soar. I don't know if they went into the red if not then very close.
The rest of the journey home was uneventful but the next morning when I started it up there was a lot of chattering from around the alternator area which lessened when I switched the lights on and faded to almost nothing when the engine got warm. Is it possible high revs did some damage the alternator drive gear, there was no vibration like there is now, and fitting the high output alternator delivered the coup de gras.
Anyone any thoughts or ideas. The one that says "The solution is simple and will only cost you a buck (or even a pound)" is the one I'd most like to hear.

Sid



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Mh434
Posts: 1512
Joined: Tue Mar 25, 2014 10:24 pm
Location: Victoria, British Columbia, Canada
Motorcycle: 1997 gl1500 SE
Previous:
1981 GL1100I
1989 Kawasaki Concours

Re: Bad vibes

Post by Mh434 »

If you don't replace the alternator drive rubbers when you replace the alternator you can get significant vibration & noise. Even if you replace the alternator with the original unit, if you don't get the rubbers in their exact, previous orientation it can cause vibration problems. Those rubbers get hard, shrink, & allow the alternator drive to move relative to the alternator itself.

The best practice is to replace them with new ones at alternator change time. They're available, and quite cheap.

When you consider that the alternator has more drag when there's demand on it, it makes sense that extra lighting being turned on could reduce vibration somewhat, because the extra drag would take up & hold much of the slack from the rubbers.

Just my logic, of course....I could be way off the mark.

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DenverWinger
Posts: 1524
Joined: Thu Jun 23, 2011 2:20 pm
Location: Denver, CO
Motorcycle: (s)
1980 GL1100 STD Vetter (2005-)
1993 GL1500 Aspencade (2017-)
1983 Trav-Lite Camper (2010-)
Past rides
1972 CL350 (1980-1988) sold
1978 Suzuki GS550 (1985-2005) sold
1977 GL1000 (2002-2006) sold

Re: Bad vibes

Post by DenverWinger »

I doubt the revs did anything, won't go much over 6000 because the rev limiter kicks in. Pre-production testing ran these engines far faster than that just to see what would break, they'd re-engineer whatever broke and test it to destruction again and again until the engine was "bulletproof".
♫ 99 Little Bugs in the Code, ♪
♪ 99 Bugs in the Code. ♫ :(
♫ Take one down, Patch it around, ♪
♫ 127 Little Bugs in the Code. ♫ ♪ :shock:

~Mark

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