G/S Gearbox transmission whine

Perilouspierre

Perilouspierre

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I have noticed that my 83 G/S has a pronounced transmission whine. It occurs in the first four gears and goes when I pull the clutch in. It is particularly marked in low gears, at slow speed when on and off the throttle. Today I took it on a run and drained the transmission fluid. The magnetic sump plug had fine filings on the threads rather than the usual fluff. I also put the bike on centre stand and run the engine in gear with the rear wheel off the ground. I could hear a unhealthy churning noise that appeared to come from both the rear hub and the gearbox, this became the whine as I increased the throttle. I have taken a video and if you listen past the engine noise you should hear it. ( I am having trouble uploading this but will keep trying) The clutch engages fine, gears are selected without problem, so what could be wrong? The gearbox and final drive where rebuilt (before my ownership) by a specialist around three years ago, since then it has covered hardly any miles at all.
 
I’d be pulling the gearbox and getting it rebuilt. Continuing to use it making that noise will only add to the parts bill
 
remove drive box , recheck , d/box may be working as a loudspeaker !

Mad Hatter said:
I’d be pulling the gearbox and getting it rebuilt. Continuing to use it making that noise will only add to the parts bill
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if noise the same do this ^^^^

who was the specialist ?

mikeyboy to the phone !

it's only money , and you can't take it with you.
 
With the bike on the centre stand your Uj,s are at a very unhealthy angle ....too be running it in gear....
 
Perilouspierre said:
I have noticed that my 83 G/S has a pronounced transmission whine.
Click to expand...
Okay so, Have you any idea what oil is in there ??

What did you put back in was it GL5 spec? and di you go for low viscosity fully synth by an chance?
Perilouspierre said:
The gearbox and final drive where rebuilt (before my ownership) by a specialist around three years ago, since then it has covered hardly any miles at all.
Click to expand...
Why not track that down and speak to them ??

I had quite a few bike over the years that seemed to have louder whine in low gears and disappeared in top gear but nothing much at all if anything on drain plugs from change to change and for the two or three that decided to pull the boxes Nothing was found and I recommended a replacement rather than the expense of a rebuild to find it just did the same thing?

Take a moment or two to assess and diagnose and check it out before just pulling the box out and lashing out £100sssss to replace When it might well do you a summer and do the box in the winter ??

Does it change gear cleanly ?

Does it feel notchy ?

Usually sparkles in the oil are a sign that the bearings are failing and I would be less prone to ride it

Not having heard the noise but "whine" tends to be gear mesh mechanical rumble more of a bearing failing


My Tip? Bung some EP90 GL5 in and see if it reduces AND monitor after maybe 100 Miles??? £10 or oil to manage the season and save pennies for a rebuild in the winter! N.B. Must be GL5 oil and not GL4 or a Hybrid oil for these transmissions

Obviously if it gets louder after some miles it needs looked at further But if it stays at the same volume??

OF course if it feels notchy or lashy and you are not confident just pull it and get it done These boxes are great and 99.9% failures are progressive with symptoms rather than simply smashing up inside !
 
I have been told this might be a dreaded circlip issue in the gearbox. As my bike is an 83 I thought this would not apply. However the gearbox number is high on the left side just below the airbox and apparently this might indicate a 1984 or later gearbox. The number is ZSA 084912 if anybody has a means of confirming this is the case.
 
Perilouspierre said:
I have been told this might be a dreaded circlip issue
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If you have this affliction the rear wheel will feel notchy when turned by hand. If your gearbox had been apart recently the guy/gal (you can't be too careful these days) who did it should remember. In your first post you mention draining the oil then running it on the stand in gear - hopefully you had oil back in it when you did that? Have you drained the rear drive and driveshaft oil to inspect? But I must say you are heading for a strip-down......
 
Gelandestrasse said:
If you have this affliction the rear wheel will feel notchy when turned by hand. If your gearbox had been apart recently the guy/gal (you can't be too careful these days) who did it should remember. In your first post you mention draining the oil then running it on the stand in gear - hopefully you had oil back in it when you did that? Have you drained the rear drive and driveshaft oil to inspect? But I must say you are heading for a strip-down......
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I cannot feel anything notchy when I turn it by hand. Yes I only ran it with oil back in the transmission. I have ordered an Engineers stethoscope and will explore furter on its arrival.
 
To inspect the rear bevel internals this is possible 'on the bike' by taking the wheel off, drain oil, brake components off (shoes, springs, brake cam) and removing the bolts to 'split' the hub. You only need a new gasket to put it back together. There are 2 M5 holes diametrically opposite which you wind in (evenly) a couple of bolts and that extracts the crown wheel without disturbing the oil seal. Once out, you can inspect (I doubt a shufti-scope will fit in). As long as things go back in the way they come out it's not a long job. Unless you find something you don't like, of course.....
 
Gelandestrasse said:
To inspect the rear bevel internals this is possible 'on the bike' by taking the wheel off, drain oil, brake components off (shoes, springs, brake cam) and removing the bolts to 'split' the hub. You only need a new gasket to put it back together. There are 2 M5 holes diametrically opposite which you wind in (evenly) a couple of bolts and that extracts the crown wheel without disturbing the oil seal. Once out, you can inspect (I doubt a shufti-scope will fit in). As long as things go back in the way they come out it's not a long job. Unless you find something you don't like, of course.....
Click to expand...
Why go near the FD, If the whine disappears in 5th gear??

I said it above and I will say it again

If it changes gears cleanly, has no stiff notchiness in rotation and the oil does not have sparkles

Stick in a good EP90 GL5 and ride it for a bit!

If it was the "Circlip" its on the end of the output shaft? As Largaider states you won;t know about it until it is too late!

Circlip failure

Circlip problem with Airhead transmission
largiader.com
 
Try a drop of that Liqui Molly
www.liqui-moly.com

Gear-Oil Additive

Contains highly concentrated MoS2 to reduce wear in manual and differential transmissions, axle drives without integrated wet differential locks and mechanical steering systems. MoS2 reduces temperature peaks and ensures quieter running and smoother shifting. The transmission heats up less and...
www.liqui-moly.com www.liqui-moly.com
 
Last edited:
DrFarkoff said:
As Largaider states you won;t know about it until it is too late!
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He's very good. After buying a bike and riding it home I looked it over more carefully and the rear wheel felt notchy when turned by hand. There was no related whine. I removed the bevel drive; it was ok. I removed the shaft and that felt fine. I turned the output flange of the gearbox and that felt notchy. I took the gearbox off and apart and found the forward bearing of the output shaft had moved towards the end of the shaft (no circlip). I reached for a spare circlipped output shaft and swapped the gears onto that and replaced both bearings, checked the rest of the gearbox and rebuilt with new seals etc. Notchyness gone and a good few miles done since. So was I too late?
 
Gelandestrasse said:
He's very good. After buying a bike and riding it home I looked it over more carefully and the rear wheel felt notchy when turned by hand. There was no related whine. I removed the bevel drive; it was ok. I removed the shaft and that felt fine. I turned the output flange of the gearbox and that felt notchy. I took the gearbox off and apart and found the forward bearing of the output shaft had moved towards the end of the shaft (no circlip). I reached for a spare circlipped output shaft and swapped the gears onto that and replaced both bearings, checked the rest of the gearbox and rebuilt with new seals etc. Notchyness gone and a good few miles done since. So was I too late?
Click to expand...
Exactly the same story with my R100R , but even with new bearings it still "wined" .
Liqui Moli gearbox (molybdenum disulfide ) had helped it quite a bit.
 
I’d suggest worn helical gears,
Only thing that steers me away is it not whining in 5th.
You suggest the gearbox was rebuilt not many miles ago but these gears may have been noted at the time and left if the bike was only doing local “bike night” trips.
The 3helical gears are pretty expensive and will push the cost of a rebuild over £1k
 
mikeyboy said:
I’d suggest worn helical gears,
Only thing that steers me away is it not whining in 5th.
You suggest the gearbox was rebuilt not many miles ago but these gears may have been noted at the time and left if the bike was only doing local “bike night” trips.
The 3helical gears are pretty expensive and will push the cost of a rebuild over £1k
Click to expand...
Thanks Mike, I cannot seem to upload a video here. However I was able to attach it in an E mail which I have sent to you, I wonder if you might take a listen for me. Pete
 
Gelandestrasse said:
He's very good. After buying a bike and riding it home I looked it over more carefully and the rear wheel felt notchy when turned by hand. There was no related whine. I removed the bevel drive; it was ok. I removed the shaft and that felt fine. I turned the output flange of the gearbox and that felt notchy. I took the gearbox off and apart and found the forward bearing of the output shaft had moved towards the end of the shaft (no circlip). I reached for a spare circlipped output shaft and swapped the gears onto that and replaced both bearings, checked the rest of the gearbox and rebuilt with new seals etc. Notchyness gone and a good few miles done since. So was I too late?
Click to expand...

Please Note from above
If it changes gears cleanly, has no stiff notchiness in rotation and the oil does not have sparkles

Stick in a good EP90 GL5 and ride it for a bit!"
Click to expand...
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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