Final drives....again

[kbada]

My oil leak, surprise surprise, has developed into 'orrible noises - clonk clonk it says - like the technical description??

Question - if you look at the hole through the final drive, does the inner steel 'tube' rotate with the wheel or should it be stationary?? As you probably have guessed, mine rotates and that seems wrong to me.....

 

[windblast]

The hollow tube should rotate. Look at the left side of the rear wheel and you'll see why!

 

[Wraithwrider]

Clonk clonk sounds completely normal.

They all clonk at slow speed when taking up and backing off the throttle.

Peter

 

[(RIP) Geriatric Germ]

Clonk clonk sounds completely normal.

They all clonk at slow speed when taking up and backing off the throttle.

Peter

What causes this as mine didn't but does now.

 

[JayGee]

Being paranoid about the final drive and other issues is a well known symptom of gs-itus brought on by taking too much notice of what some have posted on this forum. I also have a bad case of this affliction and whilst parked up on holiday in the Alps a couple of weeks ago I was horified to see what looked like oil on the rear rim (a bit like chain lube does on those blander machines where you have to oil a chain rather than top up the engine oil!). On closer inspection the oil was brake dust which had been washed out onto the rim after the ford/river I'd just been through.

The hollow axle does rotate with the wheel (they are attached to each other) so that's just looks a bit weird but is as it should be.

If the clonking is when taking up the slack in the drive with the clutch then that also is normal, although I must admit not one of the GSs best characteristics.
I took mine back to the dealers because of these clonks as I was convinced the final drive was duff but I then rode their demonstrator and that was the same. I don't notice it anymore so I think it's a case of if your listening for it you'll notice it, if not you wont. I do still check the rear wheel for play at least once a week and so far there is no movement detectable.

I got back from a 4000 mile round trip and the bike behaved perfectly so my confidence in its reliability is beginning to grow, let's just hope it continues perform so well.

 

[kbada]

clonk clonk...

I wish it was as simple as drive-line backlash - no, I don't think I want that either!!

My wife came home the other evening and said that the bike was behaving strangely and noisily.

I went to the garage, put the bike on the centerstand, started her up and let the clutch out in 1st gear. On a trailing throttle the clunk clunk made itself instantly apparent and it did'nt improves matters when gwntly opening the throttle.

It's being picked up tomorrow evening for transport to the beemerdoc's surgery so we'll see what transpires........

 

[drdata]

Re: clonk clonk...

I wish it was as simple as drive-line backlash - no, I don't think I want that either!!

My wife came home the other evening and said that the bike was behaving strangely and noisily.

I went to the garage, put the bike on the centerstand, started her up and let the clutch out in 1st gear. On a trailing throttle the clunk clunk made itself instantly apparent and it did'nt improves matters when gwntly opening the throttle.

It's being picked up tomorrow evening for transport to the beemerdoc's surgery so we'll see what transpires........

Just a comment that AFAIK, my FD is fine, but it too makes some bad clunck noises if I spin the rear while on the center stand (using the engine). It seems that the unloaded wheel wants to over-spin, slap one side of the gear, then back off and slap the other side. If I had tried that manevour feeling that my FD was bad, the sounds would have "proved it".
Regards

 

[Paul Wakefield]

I seem to remember a thread that said that you shouldn't run in gear with the back wheel unloaded (ie on the centrestand). Also recall thread said it made very nasty noise.

Paul

 

[Dreamer]

I seem to remember a thread that said that you shouldn't run in gear with the back wheel unloaded (ie on the centrestand). Also recall thread said it made very nasty noise.

Paul

I thought it wasn't possible to run in gear on the centrestand; when I tried it a while back the engine cut out when I put it into gear.. I assumed it was yet another clever safety interlock

Of course RTs might be different

 

[Paul Wakefield]

when I tried it a while back the engine cut out

I shall ignore all RT comments.

Are you sure you didn't have the sidestand down as well?

Paul

 

[KAYCEE]

I thought it wasn't possible to run in gear on the centrestand; when I tried it a while back the engine cut out when I put it into gear.. I assumed it was yet another clever safety interlock

You can run the bike in gear on the centre stand.

Your bike probably cut out because the side stand was still down

 

[ktmmark]

don't do it the backlash from the twin cylinders @ low reves will act like a jack hammer on all the transmission

 

[kbada]

Oh dear and I thought I was being clever, but now I'm even more confused than before..... but I can guarantee that it leeks oil - at least if it's got any left

 

[GSmonkey]

I must admit, when I first got mine, I was sure it was leaking oil....but it turned out to be a mixture of water and brake dust (of which there's a huge amount from the rear).

 

[TerryM]

I assume that we have the same situation as applies to a crown wheel and pinion in any automotive tranaxle or rear axle.

That being the case, the matched set of gears are set up cold so that they do not mesh completely on the drive or over run side of the gear teeth. Then noise when cold or on the stand without load, when the things can rattle back and forth with the cylinder power pulses, is not typical of operation. But when the whole thing is at operating temperature it all meshes correctly and relatively quietly.

As this lot is usually hidden away in the engine bay or under the floor pan we do not hear any clunks, but with our toy it is out in the open where we can enjoy the mechanical rumbles. Unless all the oil leaks out or they goofed in manufacturing I expect that the 100%+ design safety margin will ensure a long service life.

Has anyone heard of a crown wheel or pinion failure on a road car or even on a bike?

 

[Pukmeister]

I wish it was as simple as drive-line backlash - no, I don't think I want that either!!

Without it, the gears would grind like hell, there is designed-in backlash on the crownwheel and pinion to allow for an oil wedge and some running clearance.

 

[ktmmark]

You can check the oil level with the plug @ the back of the final drive half way up