Well.

1. Greece has a colossal amount of Beemers (believe it : in certain districts of Athens you can spot more GS - and Porsche Cayenne - than moppets and Toyotas). This maybe has to do (or is due) with the forthcoming Greek bankruptcy (unavoidable) but why bother? we live once..

2. Chief Supremo Guru Antony (there's only one Antony in Athens, he he) points that the cush drive spring and/or the "stop" medium (kinda a "washer") fail due to insufficient material strength - always in relation with the gear engagement forces applied. Antony's Chief supremo technician (known as The Merciless - he does the job with a robot like style) says other things as well that can't been written in a Noble Forum like this one. Note: in Antony's backyard there's at least 80 bikes (daily) waiting for some kind of service - that maybe gives you some clue about his aperture of experience.

3. Chief etc etc says "silent" (tiny) changes in the whole gearbox assembly it's a frequent phenomenon (I never bothered to ask him exact details) - these include a recent size differentiation in the gearbox bearing sizes (remember my recent search for non OEM bearings? - circa Sept 2010). Spring "stop" washer shape/size and the spring itself fall into that category as well.

4. Chief Troll R12S user (yours truly) says that a far simpler/better solution could be to establish some direct link between Getrag - RB Racing...or maybe better a long distance call to Japan.

But why bother? Sooner or later you'll come to Greece (Myconos, Corfu, Girls, Ouzo, Ducatis, fast boats, wild nights etc etc) and ...well..you know what they say ...seeing is believing.

Progress report...
 

Been procrastinating on this since last fall. Finally removed the Transmission and now I have to split the Transmission Case Halves. The Throw-out Bearing looks fine and there was no evidence of Brake Fluid leaking there.

Does anyone have tips/experience on splitting the Trans? I've not done it before but I do know that the Case Halves must be heated (Heat Gun I assume) in order for them to let loose of the Bearings on the ends of three Shafts inside.

Here's a couple pics of my Clutch Splines after 70K miles. I lubed them @50K miles and they're so red/rusty you'd never know it.

http://forums.pelicanparts.com/uploa...1301176913.jpg

http://forums.pelicanparts.com/uploa...1301176942.jpg

I'll post again after splitting the Trans. Hopefully it will be obvious what the source of the "Can of Marbles" sound is.

Spin that transmission spline shaft with your fingers. If it doesn't move freely in nueteral or "feels" anything but slightly resistant smooth spinning that would be your input shaft bearing failing. Unfortunately if that is the issue that is the limit of my knowledge on a fix. When its happened to me I went to a junkyard and got a new tranny but I know you don't have that luxury. If that's not the source of your "marbles" let us know what you find.

Good Idea BikerMiker...Input shaft spins just fine. Also, the Transmission never felt hot after a ride which, if it was hot, could indicate a failed Bearing inside.

I had an Output Shaft Bearing failure on my Airhead GS and the trans got very hot.

:confused:What was your Idle set at ? if it is below 1000 rpm you get the sound you are talking about:eek:

Idle speed is where it's always been so no change there. This noise appeared suddenly and there were metalic flecks in the Trans Oil afterwards. I've also done the R1200 Left Cam Chain Tensioner upgrade so that can be eliminated as a noise source as well.

Just wait till after I split open the Transmission...that'll be the end of speculation on whats wrong.

Metal in the trans oil not good!

Anxiously following this thread. I have the same exact noise on mine. Goes away with throttle or pulling the clutch in.

I forgot about this... Good thing you are taking care of that... I've been trying to think this whole time why that marble sound seemed so familiar and I finally remembered my old Mazda B2000 pickup. Same described sound like marbles in a can that was exactly it. Anyway I let it go (I had a five speed waiting in the wings) and while pulling out one day the transmission completely disintegrated inside locking up without a hint. It was full of shavings and newly made metal chunks. Very cool. Not cool if I would have been going faster than 25. Never cared about why or how just replaced it. Anyway point is that a transmission locking up on you in a snap with no warning could be catastrophic (or a good story with friends at the pub). Well... I guess the marble sound is the warning.

Got the Transmission split open today.

I drained the Bel-Ray 80w90 that I put in last fall and there were no metal flecks like the previous drain...well it was the third oil change in ~50 miles so maybe got them all out? Also the Magnet on the Drain Plug had very few metal flecks versus the previous drain.

The Repair Manual showed a Heat Gun used to bring the case up to 100 Deg C. I instead put the Trans Case (Output Shaft Bearing End) in a large Aluminum Foil Pan (cheap) and then poured Boiling Water into it. I then tapped on the upper Housing half and it came off very easily.

1) Cush Drive "Anti Rattle Disc" seems fine. I expected to see the ramps of the Cush Drive looking all beat up if the Disc was broke but the Input Shaft is as tight as a drum and the Cush Drive ramps surfaces are smooth .
http://forums.pelicanparts.com/uploa...1301790869.jpg

2) This Bearing on the end Intermediate Shaft has a "not good" feel when I spin it. The other two Bearings on this end feel fine but I'm thinking best to replace all 6 bearings. The Shifting Fork Guide (Barrel Cam) looks really good too. Surprisingly since it's made of Aluminum versus Steel.
http://forums.pelicanparts.com/uploa...1301790975.jpg

So more disassembly to do and so far found a bad bearing but not what I expected...is the intermediate shaft loaded that much?

I doubt you will find anything major wrong with it. Synching the throttle bodies usually makes it go away.

http://forums.pelicanparts.com/bmw-r1100s-r1200s-tech-forum/25383-rattling-gearbox-advice-sought.html

I would replace all six bearings while you are in there.
If you change the bearings the shafts should be checked for the correct shimming/axial play.

Cheers

I hope this doesn't lead to a bunch of people taking their transmissions apart without taking the simple steps first.

Just saying...

Thanks for all the helpful advice Guys but even a good 'ol Throttle Sync won't cure a sudden heafty amount of metal flecks in the gear oil I'm afraid. :^) Especially after 70K Miles. The zillions of Bubbles in the Gear Oil was disturbing too.

And thanks for the reminder DR, you're correct. There are measurements and shims to be mindful of when replacing bearings and such inside. Fortunately the BMW Repair Manual gives the measurements...just wish I had a stack of Shims close at hand.

Now I'm at a decision point of spening money for new trans parts versus buying a low miles used trans and hoping the alignment to the engine block is good (correct spline alignment).

Repair your own........you are into it so far already and you should be able to get most of the bearings at a bearing house inexpensively.

Cheers

Thanks DR...Yes I will replace all 6 Bearings. Closer inspection reveals they're all loose.

I wonder why they're all of the sealed type? One idea is that if the trans oil plug fell out the bearings wouldn't lock up unexpectedly?

I believe they are like that to keep the crap out. It is not so much a seal as it is a cover/protecter.....as oil will get into the bearing, so it is not completely sealed.

I have the same sealed type bearings on my KTM for the cam. It was the first time I had seen that inside an engine.

So I did a little test to see if oil would get into the bearings. I just put them in a cup of oil and watched the bubbles come out.......that told me they would get oil quite easily.......so I installed the new ones with the seal.

Cheers

Righto DR...they do leak oil. I finally got them out of the Trans cases. Stubbornness is too easy a word to describe how difficult it was to extract them from the Trans Case cavities...or maybe I need better tools? Sicher ist Sicher!!!

Anyway I've done some online research and determined that four of them can be replaced by a 6205-2RS. One is a 6204-2RS and the last one is a 6003-2RS.

The online prices I'm finding for each bearing is $2 or $3 each. OTOH BMW wants $57.10 for the 6205-2RS, $30.70 for the 6204-2RS, and $25.14 for the 6003-2RS. Are the BMW units made of "unobtainium"?..how can they think of such waaaaayyyyy off the mark pricing?

Thinking about my riding style...I accelerate semi-hard mostly and always use engine braking for setting up a curve or coming to a stop. So two prevailing forces in opposing directions placed over a twin cylinder beat...maybe the bearings succumbed to this duty cycle as the miles (70K now) accumulated?

Here's the bearings:
http://forums.pelicanparts.com/uploa...1304205028.jpg

I bought six new NTN Brand Bearings at a local Bearing Shop. Total Cost was $73.75 including Tax. According to my calculations this is $238 less than I'd pay for them at a BMW Dealer.

I checked the NTN Bearing website for specs on these new Bearings. It was interesting to note that the Static Load value is roughly half of the Dynamic Load value.

I imagine there may be a logarithmic kind of relationship between load capability and the rotational speed of the bearing such that the load capability increases rapidly and then levels off to a flat line.

This apsect of the load carrying profile makes me think negatively about aggressive off the line acceleration.

This is my 4th BMW Transmission failure (3 failures of the Output Shaft Bearing on my Airhead and now this one on the Intermediate Shaft Bearing). My riding technique must be awful or BMW Transmissions are weak or both?

Here's the specs on the NTN Bearings:
Bearing Part No...Description......................Qty...Static Load (LBF/N)...Dynamic Load (LBF/N)...Price
6003LLBC3/L627..17x35x10 Sealed Bearing....1......775/3350................1530/6800...................$12.67
6204LLBC3/L627..20x47x14 Sealed Bearing....1......1500/6650...............2890/12800.................$7.85
6205LLBC3/L627..25x52x15 Sealed Bearing....4......1770/7850...............3150/14000.................$11.90

So did we ever get to the cause of the clackety sound? I have the same sound coming from my r1200s. Only when clutch is released in neutral and engine/gearbox are warm. No noise when engine is cold. I have fitted a slipper clutch. Clutch working fine, gear box changing smoothly. Noise only in neatral with clutch engaged. No shiny bits in gear oil. I'm suspecting it's something like an input shaft bearing. Any ideas folks?