Driveshaft bearings on the way out?

[MaxB]

Hi All,

I was on tour in Spain last week on my 2013 LC (17K on the clock), and became aware of some exceedingly strange intermittent noises coming from somewhere around the back end of the engine/driveshaft area of the bike, although it was difficult to pin down the source precisely. It was a whining sound that went up and down in pitch, almost like a siren. It would carry on for a while and then disappear. It didn't seem to make any difference whether I was moving or not, or whether the clutch was pulled in. It only occured while the engine was running.

I searched the usual forums, but couldn't find anything relevant. So I gave Vines a call, to see if they had any advice. Beyond asking whether I had the extended warranty (which I don't), the fella suggested that it might be a bearing in the drivetrain, or the 'generator'(?).

Anyway, the bike got us home, thank gawd. Interestingly, I picked up a copy of MCN on the boat back, which mentioned that one of the updates for the new model GS is 'revised driveshaft bearings'.

So, I'm asking myself 3 questions:

1) Is there a widespread issue with these bearings? The fact that they're revising them might suggest so. Anyone else experienced a problem with them?

2) If there is a problem with the bearings, is this the problem that I have? What are the common symptoms?

3) If replacement is required, how grim and time-consuming a task is accessing the offending part?

Any feedback welcome...

Max

 

[matchbox]

Do you mean it does it when stationary?

 

[flatdog]

One way to determine whether its going to cost you a lot or not:
Drain the gearbox oil and see whats in it.
No parts in the drivechain are moving if it's making that noise whilst stationary.

My money would be on the alternator/belt area.

 

[MaxB]

It does indeed do it when stationary.

To slightly correct my original post, the BMW update refers to revised 'transmission shafts and transmission shaft bearing'.

What I don't know, being ignorant in these matters, is whether those components are before or after the clutch in the drive system. I can see that if they are behind the clutch, i.e. on the drive shaft side of things, it would not make the noise when stationary.

 

[autogs]

One way to determine whether its going to cost you a lot or not:
Drain the gearbox oil and see whats in it.
No parts in the drivechain are moving if it's making that noise whilst stationary.

My money would be on the alternator/belt area.

no alternator belt on a w/c,alternator is inside the engine

 

[flatdog]

no alternator belt on a w/c,alternator is inside the engine

Yes...I forgot they are inboard.

 

[NZRalphy]

Gearbox is after the clutch so if it is noisy when stood still it can't be a gearbox fault.

 

[MaxB]

Okey doke - that's helpful. So if it's not the gearbox, and it isn't the final drive, maybe it's in the clutch itself, or something prior to that.

Or could it be the alternator? I seem to remember seeing another thread where the that had packed up, but the symptoms there were a lack of charge rather than a weird noise.

Anyone know if the terms 'transmission shaft/bearing' and 'driveshaft/bearing' are one and the same, or different?

 

[matchbox]

Is it louder on the right side? In which case could well be the generator(the black thing behind the right cylinder).

 

[MaxB]

It's hard to tell which side is louder. But isn't the alternator buried in the engine, anyway? The black cylindrical box behind the right hand cylinder is the starter motor, isn't it?

 

[Ozz]

I thought so...

 

[ossa eck]

Its good to see the quality of replies hasn't slipped.

No fan belt, and an alternator that's a starter motor.

Take it to a bike workshop, get an educated guess.

 

[matchbox]

Sorry! Yes its the starter motor.

 

[MaxB]

No doubt that's what I'll end up doing, Ossa. Just posted the question in case there were any similar experiences out there that might help narrow things down a bit...

 

[flatdog]

Its good to see the quality of replies hasn't slipped.

No fan belt, and an alternator that's a starter motor.

Take it to a bike workshop, get an educated guess.

Yes, very observant of you.
Thanks.
At least we are chucking stuff on the pile including potentially ruleing out what he had been led to believe because..... the OP has already sought advice from a dealer who seems to know less than us and is only interested in warrenty....very helpfull. So jog on.

 

[ChazzyB]

Whining when stationary - that'll be the turbocharger thrust bearing. Bad news.

 

[roamer]

The gears are turning when stationary,
if you pull the clutch in does it stop the noise,
As its all running in 5 w 40 engine oil it can sound rattly especially hot engine,
My gs is quite noisy and is quieter with the clutch in , and has noises from the cam gears,

Its worth getting it checked out if its a concern,
The revised gears etc might be an attempt to improve the gear change
They are probably sourcing from john deere instead of massey ferguson
Roamer

 

[tanneman]

The following rotate when the transmission is in neutral.

Crankshaft
Clutch
Balance shaft
Starter Freewheel
Cam shafts
Camshaft drive
Oil Pump
Water Pump
Alternator
Gearbox Input shaft
Layshaft

If you select a gear then the following rotates in addition to the top

Gearbox Output shaft
Driveshaft and universal joints
Final drive
Final drive Output shaft
Flange (rear wheel mount)

The starter has a freewheel connection to the crank shaft. This means that with the engine rotating the coupling is disengaged. Engine at rest and starter motor rotating the drive engages to rotate the crank.
http://www.realoem.com/bmw/enUS/sho...-K50-BMW-R_1200_GS_0A01,_0A11_&diagId=11_5167

Warm the bike up, meaning take it for a ride. 15 min would do. Stop and listen to the engine sounds. If it still sounds abnormal then some investigation is required.

Compare it to another bike. You can try and trace the source by putting your finger or a tool against a suspect area to feel the vibration causing the concern.

Check all panels, fittings and fixings are tight and don't rattle or is in close contact with another part that can cause the noise. This will require some detailed mk1 eyeball from various angles and a basic set of tools.

A good indication of the condition of an engine is the oil. You can drain it through a filter to check for shiny bits which can indicate a worn bearing or broken gear tooth. Mostly you will just see a clump of fine black swarf if I can put it that way which is normal wear. Take a pic if unsure and some more advanced mechanics on here can guide you. Don't listen to the snake oil merchants

Either consult your local dealer or independent or ride it till something drops off and the noise stops.

 

[MaxB]

That's a very detailed and thoughtful response, Tanneman - I thank you for your time in writing and posting it.

My current memory of it is that it has done it from both cold and warm, both with the clutch in and out, and with a gear selected and in neutral. I shall now attempt to confirm that with some further experimentation, in order to narrow things down a bit, before going round to see my friendly local independent for a chat.

It's the usual frustration with an intermittent issue, in that it never does it when you want it to. But at least I'm not 350 miles from Santander down a dirt track anymore, so can take a more relaxed attitude to it...

 

[Camel Toe]

are you sure its not the exhaust flap ......sticking n squealing......