1996 R1100r clutch/gearbox

[grumpygnome]

as I was entering the traffic from a stop (slight uphill, with more rpm that normal), while switching to second, instead of moving faster, the bike lost speed with a screeching/whining sound.
Thinking 'busted the gearbox', I moved to the shoulder, killed the engine and after rocking it back and forth and switching up and down and easily finding N, I gave it another try and started it. The sound was (as if the gears were grinding) present with the clutch on, and the bike would move, though slowly. As I was a block from home, I decided to get going (whatever broke, was already broken...)
So now I've managed to get to my backyard, the question is, what it is that is broken.
Any suggestions are greatly appreciated.

Thanks

[GTRider]

as I was entering the traffic from a stop (slight uphill, with more rpm that normal), while switching to second, instead of moving faster, the bike lost speed with a screeching/whining sound.
Thinking 'busted the gearbox', I moved to the shoulder, killed the engine and after rocking it back and forth and switching up and down and easily finding N, I gave it another try and started it. The sound was (as if the gears were grinding) present with the clutch on, and the bike would move, though slowly. As I was a block from home, I decided to get going (whatever broke, was already broken...)
So now I've managed to get to my backyard, the question is, what it is that is broken.
Any suggestions are greatly appreciated.

Thanks

Unfortunately, that sounds like a failure of clutch splines, on either the clutch disc, the transmission input shaft, or both. A solid diagnosis requires removing the transmission and inspecting those parts. There could be other possibilities, like failure of the output shaft splines, but those would be revealed during disassembly to get at the clutch splines, which are still the most likely problem.

Best,
DeVern

[grumpygnome]

yea,
I just want as big a list of parts I need to order.
Once I take it apart, I want to put it back together faster. (Hopefully)
At the minimum, I will be replacing the clutch disc. Is the shaft a separate part?

[mcmxcivrs]

Making a list of parts without a clear determination of the issue is going to be a best guess situation. If the assumption of it being the splines is correct, you're going to need at minimum the clutch disc, but more likely a full clutch kit depending on the mileage and wear on the rest of the clutch. The bolts for the clutch must also be replaced as they are one time torque to yield type. The shaft is going to be the bigger issue as it is part of the gearbox and is not a simple job to replace. The entire gearbox would have to be disassembled to do so and that's outside the scope of most DIY mechanics. You could look for a replacement gearbox, but that could be a time consuming search as there are not too many out there for sale in usable condition and there are differences between years and models to complicate matters. Beyond those major items, there are likely to be other little items or problems that are found as the work is completed.

Best advice is to get it torn down to see what is really going on, then just take the time needed to source the needed parts and complete the repair properly. Best of luck with it, it always sucks to have a ride out of commission.

[m_stock10506]

yea,
I just want as big a list of parts I need to order.
Once I take it apart, I want to put it back together faster. (Hopefully)
At the minimum, I will be replacing the clutch disc. Is the shaft a separate part?

If you remove the starter motor, you’ll have a gap that will let you peer into the spot where the clutch hub sits on the transmission input shaft splines. Shine a light up onto the spot and you will likely see metal shavings all over the area. It won’t tell you you if the issue is the clutch hub or the output splines, but the repair process is the same. You will have to split the bike and remove the transmission. The shaft is part of the transmission and a much more involved repair. It’s possible that only the clutch splines are damaged, had that on my RT.

[grumpygnome]

Thanks everybody,
I was just trying to find some hope before starting the "splitting". As I do not see any way around it (short of putting for sale a bike w/no transmission or taking it to the dealer...)
Tomorrow I will start taking it apart.

[BC1100S]

I may be the odd man out here but if the issue is a failed output or input shaft perhaps a better use of your time and a more effective use of your money would be to buy another bike.

[mcmxcivrs]

I may be the odd man out here but if the issue is a failed output or input shaft perhaps a better use of your time and a more effective use of your money would be to buy another bike.

That may well be the sad truth in the end. Tearing it down to determine that will have it well on the way to being a part out if so. But lets try to maintain some hope for now that it can be saved.

[senseamidmadness]

I may be the odd man out here but if the issue is a failed output or input shaft perhaps a better use of your time and a more effective use of your money would be to buy another bike.

Depends on how adept of a mechanic the poster is. Used transmissions are readily available on Ebay and I've seen a few on our MOA classifieds as well as my local ones.

Personally, tearing through my bike to fix something, even if it means buying lots of new parts, is preferable to me than buying another one with many parts in unknown condition.

[grumpygnome]

well,
so far with the starter out I can see shiny metal pieces ("shavings?"). On my way down the "splitting".

[kbasa]

I may be the odd man out here but if the issue is a failed output or input shaft perhaps a better use of your time and a more effective use of your money would be to buy another bike.

Came here to type this, to be honest.

[AntonLargiader]

You'll need to replace the transmission input shaft (used, because it's NLA from BMW) and the clutch friction disk, and you should replace everything else in the clutch diagram from the housing on out. It's probably 12 hours of labor at my shop and somewhere over $1000 in parts. You can reduce that with used or rebuilt parts.