Clunk!

Dibbster

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Evening all,

I've just joined ukgser and I'm looking forward to lots of fun and banter.

I'm also hoping that someone may be able to offer me some advice regarding a really worrying problem with my bike... please.

So I have a 2008 R1200GS with 28k miles. I bought it from a friend having previously owned a 650 GS. Prior to his ownership it was a BMW owned off-road skills bike so it's had a pretty hard life.
Anyway my biggest concern is a knocking, or clunking noise I get when the engine has warmed up. Whilst cold it's barely noticeable.

The noise I get is a metallic knocking noise and I can feel it below the bike through my footpegs as well as hear it.
When I twist the throttle whilst cruising in any gear it clunks then, almost as if it's picking up some slack, but it also does the same thing again when I roll off the throttle or decelerate and clunks again.
If I really try I can just about ride so gently that I can avoid it, but in normal 'every day' use that's virtually impossible.

I've had it checked by an independent BMW mechanic and he says there's nothing specific he can find wrong with it, and he puts it down to the bike having had a 'hard life'. I'm really not happy with that diagnosis though - as it's either right or wrong, and it can't be right the way it is!!
Surely there must be some way to pinpoint the problem.
He concluded that the only way the noise would go away is with a gearbox replacement which obviously means a helluva lot of money and labour.

Given the nature of the noise and how/when it happens, it would make more sense to me if it were a bearing in the shaft-drive or something similar, but then I'm not a qualified mechanic by any means.

The shaft drive did end up underwater at one point a few years ago, and because there's no drainage hole the water stayed in and caused damage so the whole shaft has since been replaced with a recon one from Motorworks.

If anyone here can help me, or shed any light it would be hugely appreciated.

Best wishes to all,

Mat.
 
I was going to say big end bearings....


but the last point about the bevel taking a bath, requires more info.

does it make these noises under steady acceleration or as you come on off the throttle.... if its a clunk as you go from over run (engine breaking) to back on the throttle and it coincides exactly with throttle application …. they all do that sir (and or the bevel is a bit more worn than it should be)

if it knocks with engine revs and its getting worse stop and find the cause
 
Sounds like normal lash in the drive train

There not known for being silky smooth ;)

Two big pots sliding around give rise to a plethora of noises,


On the bike cold, mine sounds like a bag of spanners being thrown round the internals -

Get off, and stand a foot away and all you can hear is some injector & tappet noise

when it warms up you hear even less ( and even less with ear plugs in & Rammstein through the speakers ;))
 
Not something I would let drift personally, just for the sake of reliability. Gearbox, Clutch, driveshaft, bevel box - surely a decent tech can pinpoint the problem accurately for you.

Why not take your bike along to that nice Mr. Steptoe?
 
I'm sure it could be a number of things, but one datapoint is my experience of a split cush drive last year. If you search for that or Motorworks rebuildable driveshaft on the forum you will find the threads. I posted pictures of the cush damage. It became apparent afterwards that the backlash I experienced was from the split cush. I don't know if that is your issue but I could imagine the way the bike has been ridden might make that more likely. Just one idea
 
I'm sure it could be a number of things, but one datapoint is my experience of a split cush drive last year. If you search for that or Motorworks rebuildable driveshaft on the forum you will find the threads. I posted pictures of the cush damage. It became apparent afterwards that the backlash I experienced was from the split cush. I don't know if that is your issue but I could imagine the way the bike has been ridden might make that more likely. Just one idea
My penneth was also the drive shaft... and big slack somewhere. With the OPs description and yours they seem to fit? And with the hard life it seems to have had, that connection will have had an especially tough time - yea, ok, lots of other parts too - but it would seem to be transmission and the gearbox isn't meant to have 'that' much slack in it! Or the FD is in trouble?

Sent from my SM-G975F using Tapatalk
 
If you put it on the center stand and put it in gear try to turn the back wheel back and forth. If there is play in the driveshaft or other parts of the transmission you might be able find it. JJH
 
Hi JJH,
If I do that, there is at least 3-4 inches of free play where I can move the wheel back and forth. Is that normal?
 
3or 4 inches seems like a lot but can you hear anything knocking? 4 inches might be ok if there’s nothing else going on. It’s a long drive train. JJH
 
Hang on guys.

Just how and from where is the op measuring this distance from?

Sent from my SM-G975F using Tapatalk
 
The amount of play or backlash will vary depending on which gear you select. The taller the gear, the smaller the backlash should feel.
 
Anyway my biggest concern is a knocking, or clunking noise I get when the engine has warmed up. Whilst cold it's barely noticeable.

The noise I get is a metallic knocking noise and I can feel it below the bike through my footpegs as well as hear it.

It does sounds like a drive shaft problem, but it would be there all the time hot or cold and not just once warmed up. :confused:
 
Don't ignore the potential for drive shaft failure. If that breaks, the damage can be serious to very dangerous.

While you are at it, check the swing arm and Paralever pivot bearings for free play.
 
Thanks. I think I'm going to have to book it in with a main dealer to get to the bottom of the problem. Lots of helpful advice here, thanks everyone.
 
Hi all,
I took a couple of pictures of the underside of my shaft drive, after I felt quite a bit of oil under there.
Would you say this looks typical?
In theory the oil has been changed recently (or at least that’s what I’ve been charged for..) but I’m not convinced.
Thanks if anyone has feedback.

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