Drive shaft splines.

I don't doubt the shaft may seize, but does that matter ?

The shaft is designed to have no lateral movement, hence the retaining clip at the gearbox end. If the splines at the FD end seize the shaft will then be moving fore and aft with each wheel movement. This movement will be pushing the gearbox splines in and out of the retaining clip, I am sure the clip will not last long leaving metallic particles to wear the splines.
The weight of the shaft is now being thrown back and forth with each wheel movement putting lateral thrust onto the pinion? bearing.
This lateral movement is also putting load on the UJs, more so the FD end which will be bearing the weight of most of the shaft as it moves.
The shaft UJs should line up with the pivot points of the shaft housing, these will now be variably out of line with each other.
I know that water gets into the shaft housing on my bike.
I prefere my bike to operate as designed, for the sake of a blob of grease I can keep it that way.
Does it matter? to me it does.
 
The shaft is designed to have no lateral movement, hence the retaining clip at the gearbox end. If the splines at the FD end seize the shaft will then be moving fore and aft with each wheel movement. This movement will be pushing the gearbox splines in and out of the retaining clip, I am sure the clip will not last long leaving metallic particles to wear the splines.
The weight of the shaft is now being thrown back and forth with each wheel movement putting lateral thrust onto the pinion? bearing.
This lateral movement is also putting load on the UJs, more so the FD end which will be bearing the weight of most of the shaft as it moves.
The shaft UJs should line up with the pivot points of the shaft housing, these will now be variably out of line with each other.
I know that water gets into the shaft housing on my bike.
I prefere my bike to operate as designed, for the sake of a blob of grease I can keep it that way.
Does it matter? to me it does.

That's all very well. I as I've already stated above, I get the reasons for a mental reason. You're doing it again.....
Where are all the posts on here from all the shaft spline failure's ?
 
That's a nonsense question.

I would suggest, its function is to prevent rust and possible failure as per the picture. So, these boots do fail or get punctured and need replacing if they do.
By your own admission, shafts can seize on their splines so how are you going to replace the boot?
IMG-20200403-132337-thumb-jpg-c99fba373230b1f186fc075252364cb8.jpg
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Actually don't bother. I think you're a sort of troll who just likes to disagree with people even when you know your wrong.
 
Actually don't bother. I think you're a sort of troll who just likes to disagree with people even when you know your wrong.

Do you know what ad hominem means ?

/ad ˈhɒmɪnɛm/
adjective
(of an argument or reaction) directed against a person rather than the position they are maintaining.
"an ad hominem response"
 
I once worked with a person who used to say " I've only ever been wrong ONCE in my life, and on that that occasion... I thought I was wrong but in actual fact I was right".
Ring any bells ?

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Last week same subject it was 6 GS 's this week it's 8 GS's..
Something doesn't add up .
d2eb458a035a4cbeb9eae9361c435241.jpg
2d861ea6abe95e8d62400baa570adcca.jpg


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For what it's worth.

BMW have replaced a few rear drives and drive shafts due to rust to such a degree that the drive shaft was stuck to the rear drive.
The lack of a link to forum does not make the issue go away.

The driveshaft is locked to the gearbox output shaft by means of a snap-ring. This is ensures that the forward u-joint is lined up with the swing arm bearing, and movement of swingarm at this point will not cause any movement of the shaft.

However, as CPJS explains in post #122, the rear swingarm-bearing is located underneath the shaft. Thus there will be some movement of the final drive spline. This is not an opinion. This is physics.

The failure of BMW to lubricate the splines puzzles me. But they do accept the responsibility and repair the drives that have seized.

I had a chat with my local BMW pusher, and I asked about FD rusting issue.

Their attitude is that the water ingress is caused by condensation. There is no escape for moist air, and when the bike cools of and is parked, the moisture condensates onto the driveshaft. As the bike is at standstill. the shaft is higher up at the gearbox end, hence the water flows towards the final drive. He also claimed that this was more of a GSA issue than for the GS, as the GSA stands taller.

Anyway. Annual or biannual lubrication of the final drive splines is now a service item. and BMW have again started to lubricate the splines on new bikes.

Why BMW did not lubricate the LC to start with had us both puzzled....

my 2c
 
For what it's worth.

BMW have replaced a few rear drives and drive shafts due to rust to such a degree that the drive shaft was stuck to the rear drive.
The lack of a link to forum does not make the issue go away.

The driveshaft is locked to the gearbox output shaft by means of a snap-ring. This is ensures that the forward u-joint is lined up with the swing arm bearing, and movement of swingarm at this point will not cause any movement of the shaft.

However, as CPJS explains in post #122, the rear swingarm-bearing is located underneath the shaft. Thus there will be some movement of the final drive spline. This is not an opinion. This is physics.

The failure of BMW to lubricate the splines puzzles me. But they do accept the responsibility and repair the drives that have seized.

I had a chat with my local BMW pusher, and I asked about FD rusting issue.

Their attitude is that the water ingress is caused by condensation. There is no escape for moist air, and when the bike cools of and is parked, the moisture condensates onto the driveshaft. As the bike is at standstill. the shaft is higher up at the gearbox end, hence the water flows towards the final drive. He also claimed that this was more of a GSA issue than for the GS, as the GSA stands taller.

Anyway. Annual or biannual lubrication of the final drive splines is now a service item. and BMW have again started to lubricate the splines on new bikes.

Why BMW did not lubricate the LC to start with had us both puzzled....

my 2c

Thats great news, My bike is due its 24k service in march so it'll get done ? :D
 
Thats great news, My bike is due its 24k service in march so it'll get done ? :D

Yes, if the dealer has done his homework. Guess it does not hurt to ask.:D

In my country the dealers started to do this around April 2020.
 
Before you ask about spline greasing at your 24 K service, I would recommend getting the extended warranty in place if you don't already have it. As stated in last week's final drive-(athon) thread my buddies 1200 GS was only 30 months old and had covered only 4300 mls. He tried to grease his splines but couldn't separate shaft from final drive due to rust, so after complaining about roughness through the shaft BMW investigated.
They couldn't split it either and new parts were fitted. The approx cost would have been close to £3000 including labour. If they do try to grease your splines and find they are seized together you may have to pay (or try to claim on extended warranty).. or just leave it... as you aren't particularly concerned if it is rusted. However the dealership may note it on your bike's service record and it could then subsequently affect the future trade in value. Just sayin..


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Anyway. Annual or biannual lubrication of the final drive splines is now a service item. and BMW have again started to lubricate the splines on new bikes.

Can you clarify this claim. Source?
I also Have clarified, and direct from my dealership, as suspected. complete and utter bollox.
But your source confirmation would be interesting !
 
Can you clarify this claim. Source?
I also Have clarified, and direct from my dealership, as suspected. complete and utter bollox.
But your source confirmation would be interesting !

Source? My dealer.
And a couple of friends of mine that goes to the dealer for servicing the bike. (I don't have a receipt on my own. as I do my own service..)
 


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