Downshifting under load

[JimmR75]

My 06 1150GS (80K miles) has started dropping down to a lower gear when under load.  I am not touching or resting my foot on the shifter and the throttle position is unchanged when this has happens. 

 

It started with dropping from 6th to 5th when accelerating under load.  It has occassionally dropped more than one gear.  I am assuming an internal problem with the transmission but wanted input and opinions before pursuing that as the potential problem.  

 

The clutch is not slipping, it is literally downshifting under load.

 

Thanks in advance for input or suggestions.  

 

 

 

[dirtrider]

10 hours ago, JimmR75 said:

My 06 1150GS (80K miles) has started dropping down to a lower gear when under load.  I am not touching or resting my foot on the shifter and the throttle position is unchanged when this has happens. 

 

It started with dropping from 6th to 5th when accelerating under load.  It has occassionally dropped more than one gear.  I am assuming an internal problem with the transmission but wanted input and opinions before pursuing that as the potential problem.  

 

The clutch is not slipping, it is literally downshifting under load.

 

Thanks in advance for input or suggestions.  

 

 

 

Morning  JimmR75

 

Any chance that your foot (boot) is somehow contacting the shift lever when the problem is occurring? 

 

Otherwise look at your shift lever & all it's linkage for contacting anything.

 

Then make sure the little shift lever on the transmission stub shaft is not loose with the pinch bolt worked out enough to contact the trans case.

 

If all the above is good then you probably have an internal transmission problem like worn bearings or bent shift fork. 

 

Is that a real 2006 1150GS? I have seen a couple of late 2005 1150 GS-A (Adventures) but this is a first if it is a real 2006 1150 GS.

[JimmR75]

When this first happened I suspected the same thing regarding my foot position, so have been very cautious and aware of my foot placement.  It has definitely not been the result of any inadvertent input on the shift lever.  

The linkage appears correct and intact, leading to the suspicion of an internal problem.  The part that makes no sense is when it drops multiple gears, not just down to 5th.

 

It is titled as a 2006 and I believe that it is a GSA.  

 

[dirtrider]

29 minutes ago, JimmR75 said:

When this first happened I suspected the same thing regarding my foot position, so have been very cautious and aware of my foot placement.  It has definitely not been the result of any inadvertent input on the shift lever.  

The linkage appears correct and intact, leading to the suspicion of an internal problem.  The part that makes no sense is when it drops multiple gears, not just down to 5th.

 

It is titled as a 2006 and I believe that it is a GSA.  

 

Morning  JimmR75

 

Are you sure it is actually dropping 2 gears (do you need to re-upshift twice to get back to 6th gear?)

 

If it just feels like it is dropping 2 gears but no upshifting required to get back to high gear then suspect your trans input shaft splines are slipping (stripped). Not an uncommon thing on the BMW 1150 6 speed motorcycles.