GS1000 mystery noise...transmission bearing? WITH VIDEO

[80GS1000]

Got a bit of a whirring noise coming from the bottom end of my 80 Suzuki GS1000 from behind the countershaft sprocket cover. It's noticeable at idle and gets louder as the RPMs pick up. I think it might be a bad countershaft bearing but I'm not sure. Any thoughts? So far I've tightened the clutch hub nut and adjusted the cam chain tension with the manual tensioner. The noise seems to be getting worse with more time.

http://www.youtube.com/watch?v=WAugUCDyl14

Thanks for any insight.

[blowerbike]

counter shaft is not turning while your sitting still.
maybe input shaft bearing(s).
something to try if your bored.......
remove the entire clutch side and put the cover back on.
start bike and listen to see if the sound is gone.
if so i would say input shaft bearings.
your engine will be fine to run for a few seconds with out oil pressure.
trust me on this and it will rule out a few possible problems.

[TeamDar]

Try pulling in the clutch lever. With that pulled in the input shaft and input shaft bearings will not be turning either.

[chef1366]

Starter clutch.

[Nessism]

I agree with Bill. I'd check the starter clutch next.

[blowerbike]

if the starter clutch is trying to engage while running then yes.
the bike sounded to start/crank ok on the video.
the owner may add more info as to the starting sounds of the motorcycle and if it has changed in the last few days/weeks ect...
ive had starter clutches lock up before and sound like an airplane prop spinning.
spun the guts right out of the starter to.
this was a worst case senerio as (ALL) of the starting mechanism ended up being trashed.

[SqDancerLynn1]

May very well be the starter staying engaged. I had it happen on my 850 when I was up at the crest. Would not start after lunch, just popped the clutch and went home. When I removed it The starter was completely torn to pieces

[gs road racer]

I'd guess starter drive pull the cover and rotor you'll probably find the three screws that hold the drive onto the rotor are loose.This is quite common there may be some damage there. Replace parts & change the oil/filter , check for metal. If the clutch/drive shaft bearings are gone they'd be the first ones I've ever seen. Also check if there is any play in the crank end, put a dial indicator on it use the rotor bolted back on to see if any up and down if you can get more then .001-2" or feel clearance then that main bearing needs replacement (not a frequent occurrence but does happen) Let us know what you find!

Try pulling in the clutch lever. With that pulled in the input shaft and input shaft bearings will not be turning either.

You would also have to put it in gear to prevent any rotation of the shaft, if it's in neutral it will still turn.

[80GS1000]

Found a likely culprit. Took off the stator cover and lookie here, a couple teeth are broken off the big starter clutch gear.



I have a new starter clutch in my parts stash. Should I take the bike to a shop to have them pop the generator rotor off? Aside from that, how difficult of a job is it to do this repair?

Also, does the starter idler gear keep turning after the motor has started? Wondering if this noise was because the idler gear turns on the big starter clutch gear and gets louder as the crank spins faster.

[srsupertrap]

If you can break the bolt loose that secures the rotor I have read you can use the swingarm pivot bolt to remove the rotor off the shaft. Don't know about the other stuff

[Nessism]

It's true about the swingarm pivot bolt...or any bolt with the proper threads. The hard part is getting the rotor bolt off.

[chef1366]

Do you have an electric or air impact?

[blowerbike]

Do you have an electric or air impact?

sounds like neither.....

[80GS1000]

Yep, got a Dewalt electric impact...

[chef1366]

Yep, got a Dewalt electric impact...

That'll get the bolt out and the rotor off. I'd get a proper puller. Are there threads on the inside of those rotors?