A little whine with your ride sir?

[Argee]

Hi all,

I've started to notice a little bit of vibration/whine when I decelerate on my 1982 GS1100GL. If I slow down gently it's okay, but it's noticeable if I close the throttle at speed.

I'm going to check the oil levels at each end of the driveshaft, but I wondered if any other 'shafty' owners have come across anything similar.

Yours in anticipation,

Argee

[Nessism]

The secondary gears on those bikes are a weak spot. Hope it's not impending doom.

[Argee]

Oh dear! Me too!

[Steve]

The good news is that the repair part is readily available. Still used in some bikes available NEW at your local dealer.

.

[Argee]

Ed and Steve, is there any way to diagnose the fault before taking things apart?

[rustybronco]

I'd start by looking for loose bolts and (or) play in the drive shaft's u-joints.

[Gorminrider]

This is from the archives per whining . If you have the fairly common problem of the broken stud on the secondary..... To understand it, search "Zook's syndrome"
here's how I began to figure out I had the problem...

Your descriptions still sound like a broken secondary drive. With the bearing preload gone, the gears are not aligned and make a loud whine when under load, and no noise when not under load, ie, accelerating and decelerating. A quick test: Unclamp and pull back the rubber boot where the drive exits the engine/transmission case until you can see the drive shaft coupling. Poke it with a screw driver and see if it moves side-to-side or forward-backward. There should be no movement.

from here

http://www.thegsresources.com/_forum/showthread.php?65157-GS650-gearbox-or-final-drive

You might have something else going on but all Shaft drive bikes need be aware of this broken-stud/"zooks syndrome". Called Zook's because he wrote a detailed pdf that is at basscliff's
BikeCliff's Website

[Argee]

Thanks for your inputs so far.
I've not yet had the chance to take anything apart, but I did try rotating the back wheel, and it feels different. It rotates more freely and without the little bit of play that it used to have. I'm guessing that the pre-load has gone.... :-(

[Argee]

Update time.....

Well, I checked the universal joint where the drive shaft attaches to the engine and it's nice and solid.

Then it was back wheel off and final drive off.

It too me a little while to realise it, but the sleeve that came off at the back of the driveshaft should have been secured to the final drive unit. It seems like it's exactly the same failure as Mr Zooks had - but the other end of the driveshaft.IMG_20180602_170516.jpg

[Argee]

The nut that has sheared off seems to be much deeper in the sleeve on this part when compared to Mr Zooks' issue.
Thoughts? Will the same repair work?

IMG_20180602_171105.jpg

Although the photo of the nut doesn't show it too well, it's probably an inch and a half to 2 inches recessed.

[Nessism]

I "think" the same repair should work. If you can get down inside the cavity to do the work.

Those parts are relatively common in the USA but not sure about UK. I'd check out parts availability before going down the repair road.

[Argee]

All back together and working again. 😁
Thanks to Simon for selling me the replacement part.
...and thanks to you for all your advice - as usual!

IMG_20180615_191929.jpg