gearbox possible problem?

[alkis]

i have a strange noise from the transmision on 4th 5th and mainly at 6th gear at around 3 to 4000 rpm. It can be felt through the pegs mostly than really heard but it is there. I can feel it when i am riding at constant speed but not when accelerating. It is periodical and it gets faster as the Kph rise but it dissapears when i reach 4000 plus. If you have any ideas on how to check what is wrong (if there is something wrong at all) please share

Thanks a lot

oh i forgot i bought it used with 85000Km (2001 1150 gs)

 

[oblertone]

Check the oil level ...

... then buy some ear plugs; they all sound on the brink of disintegration anyway. Just ride and enjoy it until it fails, then fix it

 

[alkis]

i guess i should do just that

 

[Colban]

i have a strange noise from the transmision on 4th 5th and mainly at 6th gear at around 3 to 4000 rpm. It can be felt through the pegs mostly than really heard but it is there. I can feel it when i am riding at constant speed but not when accelerating. It is periodical and it gets faster as the Kph rise but it dissapears when i reach 4000 plus. If you have any ideas on how to check what is wrong (if there is something wrong at all) please share

Thanks a lot

oh i forgot i bought it used with 85000Km (2001 1150 gs)

It seems to be not unknown for the early g/boxes to have a slightly noisy 4th gear,but if you are having vibration in the top 3 gears,it may be a sign of bearing wear in the box.Have you tried a different grade of oil at all?.
Remember the spec to use is GL5 sae 80/90 but a lot of the Yanks on ADVrider seem keen on 140 weight oil.May be worth a shot.
I would also start to be on the lookout for a more recent,good condition gearbox to fit when you come to a clutch change.
Thats how i fixed my noisy box.

 

[johnl]

sounds like your drive shaft has been put back in 'out of phase'. Lots of different opinions on this. Most say you can just pop the final drive unit back on any old how (including dealers ) but i believe it has to be put back on so that the two UV joints are in phase. If their not you can get an increased oscilating vibration felt through the pegs at 3-4000 rpm, gear changes can be more clunky and a shudder can be felt through the front brake.

As I said most disagree with me on this one but its certainly worth checking the alignment.

 

[davegs]

sounds like your drive shaft has been put back in 'out of phase'. Lots of different opinions on this. Most say you can just pop the final drive unit back on any old how (including dealers ) but i believe it has to be put back on so that the two UV joints are in phase. If their not you can get an increased oscilating vibration felt through the pegs at 3-4000 rpm, gear changes can be more clunky and a shudder can be felt through the front brake.

As I said most disagree with me on this one but its certainly worth checking the alignment.

I have alway sput my drive shaft back "in phase", being a "bevel box experinenter" have done it a few times. But there's no mention of it in any BMW manual I've ever seen, good write up sbject in the amaeriacn club owners mag couple of years ago. Have noticed a noisy fourth gear on my 1150 GS but always seem to be in that gear quite a lot, traffic etc, so think it's just wear. Just ride it and enjoy if it gets worse get it looked at but these boxes are like tractors so don't panic. Must go and play with my latest bevel box.
dave (beveling along) gs.

 

[DrFarkoff]

sounds like your drive shaft has been put back in 'out of phase'. Lots of different opinions on this. Most say you can just pop the final drive unit back on any old how (including dealers ) but i believe it has to be put back on so that the two UV joints are in phase. If their not you can get an increased oscilating vibration felt through the pegs at 3-4000 rpm, gear changes can be more clunky and a shudder can be felt through the front brake.

As I said most disagree with me on this one but its certainly worth checking the alignment.

Okay John Describe your "in Phase" I did mine as near as I could to the 90 degree but It's not close enough

So another description would be welcomed?? So I can try that when I cahneg the gearbox very soonly

 

[johnl]

The UV joints need to ( in my opinion ) be aligned in phase. To do this some people shine a torch up the inside of the swing arm when re attaching the bevel box but this way is not very accurate. The best way is to remove the swing arm and visually line the uv joints up. They will only go correctly one way as there is an odd number of splines. Once they are lined up, I put the bike in gear to prevent the drive shaft rotating and mark on the bevel box ( where you place the rear wheel ) the position of the splines on the bevel box. You then have to seperste them, reattach the swing arm and re incert the bevel box ensuring the mark you made previously on the rear wheel final drive is still in its correct position ( The mark is a line drawn across the final drive rotating bit and on to the non moving case of the bevel box. This line needs to remain intact to ensure zero rotation of the splines. If it has broken, re align it.

As far as the UV joints being in phase, they should look like this

As I said previously some folk thinks it makes no differance. I have spoken to mechanics at two dealerships who both looked at me like I was a fool and had no idea what i was on about. of courrse i might not

 

[alkis]

Whwn i bought the bike i changed its pivot bearings and i aligned the joints correctly so it must be something else. I noticed that the frequency of the vibration is the same in 3000 rpm for all the gears but it can be felt more in the top three. So i assume it has to do with the first shaft of the gearbox since the second is speed related while the first is rev related...


If i end up with a faulty gearbox is it cheaper to repare it (myself) or buy a used one??

 

[Colban]

Whwn i bought the bike i changed its pivot bearings and i aligned the joints correctly so it must be something else. I noticed that the frequency of the vibration is the same in 3000 rpm for all the gears but it can be felt more in the top three. So i assume it has to do with the first shaft of the gearbox since the second is speed related while the first is rev related...


If i end up with a faulty gearbox is it cheaper to repare it (myself) or buy a used one??

At a guess,it sounds like a bearing is on its way out.If you are going to fix it yourself,it would be best to change all the bearing and the seals.
That would not be too expensive.Time consuming yes.
Bemilten,on ADVrider had a similar problem about a year ago and went through,with pictures,his gearbox rebuild and the problems he had.
Alternatively,buy a good used box and fit with a new clutch at the same time.
As i said before,just use the bike while you locate the new box.

 

[Neil W]

Check the final drive (bevel box ) bearings first