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SteveH
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Joined: 10/23/2011
Posts: 115

My R100 seems to have developed a gearbox 'whine' in all gears especially after i have ridden the bike for a few miles.
Only thing is it still seems to do it when i pull the clutch lever in , you can here the noise go up and down if i make the revs go up and down .
I have checked the throw out bearing which seems ok and changed the gearbox oil , doesnt seem to have made any differance.

Any ideas ?

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Steve H

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6327
What year is the bike?

What year is the bike?

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

khittner
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Joined: 02/15/2012
Posts: 364
What did the crud look like

What did the crud look like on the drain plug when you changed the gear oil? I'm not an expert, but I'd be girding my wallet for a tranny rebuild soon. If it had flakes or chunks on the drain magnet, plan for a tranny rebuild yesterday. Your wallet will prefer bearing replacement to damaged gear replacement, so I'd recommend no further non-diagnostic movement of the bike and tranny until its sorted.

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Konrad

SteveH
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Bike is 1992 done 60k

Bike is 1992 done 60k miles.
The drain plug just had a bit of very fine paste not really gritty.

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Steve H

schrader7032
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VBMWMO #7032
San Antonio, TX
Joined: 10/27/2006
Posts: 6327
Your model is in the range of

Your model is in the range of '85-95 bikes where a circlip was removed from the transmission. The issue that can happen is that the output shaft bearing moves and creates pressure on the bearings and the shaft. Read about it here:

http://www.largiader.com/articles/circlip/

It is a good idea to check the fuzz that is on the transmission drain plug...if anything begins to show up other than typical fuzz (no solid particles), then you're OK. But as soon as larger pieces begin to show up, it's time to rebuild the transmission. It seems this is what's going on with yours.

Some people run a product added to the transmission fluid to possibly help with this. One product is Guard Dog Moly 525 although I hear that it is being discontinued. Another product is made by Dow Corning called Gear Guard M.

Something else you might want to consider...when was the last time the input splines on the transmission were lubed? Could be that this is the source of the whine.

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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2

SteveH
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Posts: 115
I think i might pull it of and have a look

I think i might pull it of and have a look.
The only thing i can't understand is that with the clutch lever in , which disengages the engine rpm from the input shaft,the 'whine' is still there? And changes as i increase or decrease the rpm .

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Steve H

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