Vibration only in 4th gear at around 3500rpm

[majaem]

Hi all,

Just bought an 05, 1150gsa at 39000 miles.

The bike runs fantastic in all gears except 4th gear. Once in fourth gear there is a pronounced rhythmic vibration which you can feel through the seat / rear of bike.

Could this be a fault in the gearbox?

Anyone any ideas?

Thank you

Mark

 

[Pete D]

You are not alone....see thread 3 below (currently).

Sounds like a 'feature'.....


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[Colban]

My original Y2K GS had the same noise in its first gearbox.Swapped box,noise went away.

 

[Pauly S]

and again

They all do it in 4th gear, only the gsas though, its to do with an alignment of the all the drivetrain,the crank and flywheel,gearbox and fd,the only way I can explain it, its like a total eclipse of the sun,when all the planets whirr round,after so many cycles the moon masks the sun,its the same with the gsa in 4th,every 75yds or so,thrummmm,thrummm thrummm,doesn't do it in any other gear.I had a nearly new 115gsa years ago, I even changed the gearbox, no difference, its the way they are.If you ride the std 1150 it doesn't do it, the gear ratios are different

 

[majaem]

Thank you for the advice.

Mark

 

[mspenz]

Hi Mark, more throttle make it go away

 

[majaem]

Thanks to all who replied.

Just an update regarding 4th gear issues.

The bikes been into my local bmw dealer today and the head tech took it out for a test run and thankfully agrees that there is a definitive vibration in 4 th gear. As the bike is still under warranty he is going to speak to BMW and come back to me with an answer.

I will of course post their findings for others on here with the same or similar issues.

Thanks

Mark

 

[Pete D]

Update awaited with great interest. Good luck!


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[majaem]

Well after a month I'm now able to update you on the 4th Gear vibration. So here it goes, Once Upon a Time!!!

My R1150GSA was booked into BMW for a test ride to check out the vibration in 4th gear. It was decided by BMW to book it back in the following week for tests and they can contact their helpdesk to guide them on possible problems. The bike was taken back and the warranty people authorised the replacement of the output shaft bearing but after fitment and on the test run there was no significant difference so the gearbox was stripped and all six main bearings replaced plus seals replaced (im not mechanical so not sure what seals).

I collected the bike and was told there were no problems with the gearbox, no metal chips and all grooves were spot on and now with the new bearings / seals the vibration is a lot better. Took the bike home and I agree the vibration was very much better and almost unnoticeable so was very pleased with the job.

Next day went into the garage and found the bike in a puddle of oil so it went straight back to BMW...

It appears one of the seals replaced failed so a new one ordered / fitted then they put the bike on the computer which showed a faulty potentiometer so that was ordered and fitted. The bike was then put back on the computer and then showed a faulty Lambda sensor so that was ordered and replaced.

I collected the bike yesterday and it runs a treat!!!!! What a difference and as smoothe as silk and the gears no longer clunk.

So in conclusion, I don't know if the vibration originally noticed was exaggerated by a faulty potentiometer / Lambda sensor Or any other part replaced but all I can say IMO is that if the original vibration was a 10 out of 10 the vibration now in 4th gear is about a 3 out of 10 (but still there).

AND as far as BMW are concerned they were great and so much so I sent an email to the dealer principal thanking them for the work Plus I had a NEW GS LC as a loan bike whilst they had my bike.

So not sure if this actually helps anyone with the original question about 4th gear vibration but that's whats happened over the last month.

 

[Pete D]

Strewth.......

At least you can be sure of no more major issues.......for the next few weeks at least!

I now give my, not too intrusive, vibration in 4th a 'stiff ignoring'

Cheers for updating us. Great service from the dealer...exactly as you would hope for.

Pete