Gear selector shaft

[cmm1150rt]

(2004 12GS) Eighteen months ago I replaced the gear position pot (no water ingress, just worn out).

In Feb this year I took the bike in for a major (36k miles). They found gearbox oil leaks (and replaced the seals) and opined there was a gearbox problem, so dismantled the box. Found nothing wrong, so reassembled and deigned to not charge me for that as it was Their misdiagnosis, so that bit doesn't appear on the invoice.

Couple of weeks ago (only 7k miles later) it stuck in a false neutral (thank heaven) between 5 and 6 (on the M4 in the evening rush-hour).

Apparently the selector shaft seized. They then said the sensor pot had failed (again). No prob, under warranty. Next phone call - not a failed pot, new selector shaft requires different pot (so Their highly-trained 'technicians' didn't know that, then).

I'm taking away the bits They replaced and have an engineer lined up to investigate. I've asked if they have any idea why the shaft seized, but They don't.

I'll pick the bike up, pay, ride away minus an arm and a leg, get my ducks in a row and see what happens.

Anyone have any experience/advice/knowledge about what may have happened or whether it's worth getting fierce about it? I know, it's seven years old, but only 43k miles (couldn't ride it for four of those years, and use the 80G/S a lot).

Ta muchly in advance.

/Cynthia

 

[TeaPig]

When you say the gear selector shaft do you mean the thing inside the gearbox (to which the gear position indicator attaches ?)

can't see how the internal shaft would seize as there's next to load on it and it's swimming in oil. I could imagine a fault with the selector mechanism, however, which may stop any movement on the gear lever from being transmitted to the selector shaft

Generally the gearboxes on 1200's are strong except for seal failures on the earlier bikes though rare failures have been reported.

Unless you can prove the problem is related to the work done in Feb I don't see you have much of case against the dealer

 

[cmm1150rt]

When you say the gear selector shaft do you mean the thing inside the gearbox (to which the gear position indicator attaches ?)

I believe so, but I haven't seen it yet.

can't see how the internal shaft would seize as there's next to load on it and it's swimming in oil. I could imagine a fault with the selector mechanism, however, which may stop any movement on the gear lever from being transmitted to the selector shaft?)

I'd agree.

Generally the gearboxes on 1200's are strong except for seal failures on the earlier bikes though rare failures have been reported.

Unless you can prove the problem is related to the work done in Feb I don't see you have much of case against the dealer

I was thinking more BMW actually. Just have to see what the engineer says. But I have to say that a gap of only 7k miles between a gearbox being dismantled and pronounced perfect, and it failing dismally, doesn't totally convince me (if it were an airhead 5-speed box it would be a different thing altogether).

 

[TeaPig]

I was thinking more BMW actually. Just have to see what the engineer says. But I have to say that a gap of only 7k miles between a gearbox being dismantled and pronounced perfect, and it failing dismally, doesn't totally convince me .

I understand what you say but based on the record BuMW seem to have for admitting fault you may have a struggle on your hands. Let us know what's gone wrong when you find out the details.

Good luck.

 

[cmm1150rt]

I'll let you know. Might help someone else.

Incidentally, if the selector shaft was redesigned such that the original sensor doesn't fit (and it's a pretty simple soul), that's another duck to get in the row - fashion stuff aside, they don't usually change a design that works well and doesn't fall apart.

 

[Andy Michael]

I had a similar problem years ago on my old 2004GS turned out to be one of the bushes on the external part of the selector that had caused the problem, took lessthan 30mins to sort out if I remember correctly, was fine after that

 

[autogs]

I had a similar problem years ago on my old 2004GS turned out to be one of the bushes on the external part of the selector that had caused the problem, took lessthan 30mins to sort out if I remember correctly, was fine after that

yea but were asuming that the dealer checked the obvious first(i had a seized shaft once as well)they must have checked this,tell us they did please

 

[TeaPig]

yea but were asuming that the dealer checked the obvious first(i had a seized shaft once as well)they must have checked this,tell us they did please

Yeah, I thought of that too as it happened on both my 1150's, but surely...

 

[cmm1150rt]

Dead bits

So, the selector sleeve on the layshaft is jammed on the splines, right in the middle of its travel (hence the false neutral).

The rest of the shaft looks absolutely perfect, as are the bearings. The selector fork isn't awful, but I wouldn't want to recycle it. Not sure about the selector drum (machined alloy casting) as I've never seen a new one - what looks like damage may not be as it's pretty even and clean.

It'll require a large amount of brute force to dislodge the sleeve and find out what's underneath. The parts of the splines I can see look completely undamaged.

Total mystery. Perhaps Mr.Scriminger will be able to enlighten me.

 

[TeaPig]

So, the selector sleeve on the layshaft is jammed on the splines, right in the middle of its travel (hence the false neutral).


It'll require a large amount of brute force to dislodge the sleeve and find out what's underneath. The parts of the splines I can see look completely undamaged.

Total mystery. Perhaps Mr.Scriminger will be able to enlighten me.

That takes some doing. Maybe it popped out of gear under heavy load with sufficient force transmitted to the selector forks that they have been momentarily forced out of alignment leading to all sorts of confusion (technical term ) between the internals? no idea really but make sure the selector forks are not bent or badly worn. I had an 1100 that wore the selector forks until it wouldn't properly shift into top