What can cause a broken gearbox case - output bearing?

[Magwych]

I am looking at buying a 2nd hand gearbox fir the input shaft. Mine is likely gone, the casing of the shock absorber spring coming apart. I would nirmally not have rebuilt the box with the shaft in that condition but BMW were redesigning it and could not even offer an availability date, let alone the part, when I was rebuilding. I bought 2 hand shafts that were in worse condution than the one I had.
Time and circunstance xhange, I am now time rich and cash poor but have a terrible clunk from the box. I have found a 2nd hand fearbox from a later model, with the revised input shaft but the casing is split open around the outout shaft bearing. Are there known issues that can cause this specific damage? Sone firm of debris inside the gearbox is obviously one, that is ny risk, but could a failing UJ in the drive shaft have caused enough vibration to break the gearbox casing?

 

[Santa-2512]

Pm Mikeyboy

He is the guru.

 

[Ijustwanttoseethephotos]

Earlier or later input shaft?

 

[Ijustwanttoseethephotos]

Earlier or later input shaft?

Delete. Wrong thread!

 

[Magwych]

Earlier or later input shaft?

I have the earlier , 2008 input shaft. I want to install the later version - if I can find one

 

[MWH]

This the damperd one? Mines gone and rattles but the general consensus is to just ride it as it won't get worse. Seen two types, the one with a metal shield around it that comes off and one with a spring. Are they interchangeable?

 

[Magwych]

This the damperd one? Mines gone and rattles but the general consensus is to just ride it as it won't get worse. Seen two types, the one with a metal shield around it that comes off and one with a spring. Are they interchangeable?

There is a spring that pushes 2 knuckles together, with a shield around the outside to hold the spring and give it tension. The changes made to the input shaft are how that shield around the spring is made. It was a pressed metal part, with a 2 halves joining in a tenon type arrangment aling its length. They suffered stress fractures where the ends were formed over to keep the assembly together. The outer case would then come apart enough to release the spring tension. On input shafts where the spring can clearly be seen this outer case has detonated and the pieces wil be lying in the bottom of the gearbox. All 3 types of input shaft are interchangeable, the original, which had some issues, the '08 on which was worse and the 2020 on shaft used in RNineT series

 

[botus]

photos would be nice

a recent post said if the box is clunky its the cush drive failed - mines is getting worse - but it makes for great gear changes - a little nosy if u mess up (and seems to be getting louder) - but at least you can feel you changed and not got some random false neutral - which I come across far more on the 10k mile 2011 GSA and a f horrific stiff change on a 400 mile R1300GS and I found a false neutral on that in 4th the other day - quick shift shit

 

[MWH]

The part number for my 09 is the same as the part number for the RNine T. Thought bmw might have learnt, unless that part is upgraded somehow. Pity there isn't a fix to save having to replace the whole thing.

 

[Magwych]

The part number for my 09 is the same as the part number for the RNine T. Thought bmw might have learnt, unless that part is upgraded somehow. Pity there isn't a fix to save having to replace the whole thing.

23009457822 was introduced on August 1 2020
It superceded
23008563018 which was fitted from May 4 2015 to September 2 2022
Which superceded
23217709853 which was fitted from
May 1 2009 to May 11 2015

I cant find the part number for what was put inside my gearbox in March 2008, I think BMW maybe do not want to acknowledge that version. When I rebuilt the gearbox back in 2015, BMW had withdrawn 23217709853 but could not supply 23008563018 due to supply issues. I bought 2 2nd hand input shafts from different places (James Sherlock, Motorworks); both were in a worse state that my own. I think that eas because akthough my mileage was high (140,000 miles), it was mostly motorway in the UK, France and Spain so a gentle life.
The bearings are easily removed and replaced but nothing else is doable without special tooling. That spring, for example, has a high spring rate and needs compressing to remove its retainers safely. Once removed no replacement part numbers are listed for the clips. I do wonder if a polyurethane stop might have been better...

 

[Magwych]

photos would be nice

a recent post said if the box is clunky its the cush drive failed - mines is getting worse - but it makes for great gear changes - a little nosy if u mess up (and seems to be getting louder) - but at least you can feel you changed and not got some random false neutral - which I come across far more on the 10k mile 2011 GSA and a f horrific stiff change on a 400 mile R1300GS and I found a false neutral on that in 4th the other day - quick shift shit

These photos are of the 'box on EBay that I am looking at. You can see how the gearbox case has broken up around the output shaft bearing.
Mine is fine(ish), apart from the loud clunk between gears. Measured at the tyre outside diameter there is 50mm free movement in 1st, which increases to 130mm in 6th as I move the box through the gears. I know the input shaft was showing stress fractures when I rebuilt it back in 2015. They won't have healed themselves. The clunk does seem to have become worse, although I had little chance to use the bike from 2017 to 2025. So, it could just be my memory that is failing ..

 

[botus]

wow - has is slid and ground itself a hole?

I'm confused here https://www.realoem.com/bmw/en/show...25-BMW-R_1200_GS_04_0307,0317_&diagId=23_1015

I thought they gave up selling individual parts and it was just the entire pre-built thing you could get (mine's an late original looking one)

 

[MWH]

Could the damage on that box be from an accident? Shaft taking an impact and breaking it?

 

[Magwych]

Could the damage on that box be from an accident? Shaft taking an impact and breaking it?

Yes, it could. That is what I am hoping for.
The seller does not accept questions on eBay, ehich is annoying. They allege to be a private seller yet hoave over 1000 items for sale, clearly a bike breaker. The only want €130 for the whole gearbox, ehich is a good price, if the casng had not split because the insides have detonated and tried to leave.

 

[Magwych]

wow - has is slid and ground itself a hole?

I'm confused here https://www.realoem.com/bmw/en/show...25-BMW-R_1200_GS_04_0307,0317_&diagId=23_1015

I thought they gave up selling individual parts and it was just the entire pre-built thing you could get (mine's an late original looking one)

You are right. Until the model update in 2008 it seens that they were an open spring, as seen in the link you posted. Mine is a 0380 model, from March 2008, with the later caged device.
These are a xouple of photos I took ehen it was apart, you can see the stress fracture in the case starting and the broken component inside the casing.