Fix for rusty shaft ? Discuss
- Thread starter Tripleblack13
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Tripleblack13
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I did the same on my last bike.. same place, but use a small rubber bung from our paint shop to seal it.. pull it out when you wash it or it gets wet
Did you actually see water draining from the hole ?
Also did you drill into the swing arm at a 90 degree to it or directly upwards ? ( if that makes sense ?)
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Never had water coming out. tried not to get the bike wet as I hate cleaning the things..... but did it more to get air in as 'others' on here have had problems when fully sealed with interal presure, either blowing the rubber bellows out or sucking it in...
if it was a dry day I'd always keep the plug out.
I drilled the hole at 90 deg to the small pad....
https://www.ukgser.com/forums/showthread.php/505072-Got-Shaft-Rot-again-WTF
if it was a dry day I'd always keep the plug out.
I drilled the hole at 90 deg to the small pad....
https://www.ukgser.com/forums/showthread.php/505072-Got-Shaft-Rot-again-WTF
Deleted account 191119001
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I wonder why the bump was designed in the shaft at the beginning, maybe for this purpose ???, and then BMW marketing and legal dept backed of saying that would mean we admit to rusty shafts, and last question would this not weaken the shaft structure, if not damn good idea me-thinks, and if doing this good shaft flushout should be done, no metal bits creeping up the shaft into the gearbox.
Another lazy post just like the other thread. 0/10
Alan R
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Wrong sir, have you not realised this is the spoon feeding thread area, they ask and we do all the groundwork, and if not as they like, pitchforks at the ready, beaver and Warlord should get a ton of credit for this already.
I think thats exactly why the bump is there.. thick area in the casting to put in a drain.. drilling a small hole in it will not give issues given its position.. my hole was 4mm and as said, I put a rubber masking plug in it...
That bikes gone now.. but if I keep this one, I'll be doing exactly the same thing
Delboy777
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Was also thinking a quick blast of WD up there now and again wouldnt hurt either.
Yeah, I was mentioning and discussing this 'drilling a hole' idea with Beaver (off-here) a while back.
My bike is due for it's 18000 mile service soon, so I'm going to rip out the shaft again for inspection.
As I've already greased and sealed in the top half of the shaft, so it's airtight.... and then sealed in the bottom half of the shaft, so it's airtight.... I've experienced pressure changes inside the shaft over the past few thousand miles. This has shown itself in the form of either sucking in the bottom boot (under vacuum) or inflating it like a small balloon. I've been manually depressurising it by pressing my bike key onto the boot lip to break the seal.
As this should not be happening, my concerns with this are:-
a) If water gets in, it definitely can't get out. So considerations for moisture/condensation etc.
b) As the shaft heats up, the heat can't escape. So what are the implications on running temps.
c) As the pressure builds (as the shaft moves up and down, it needs to draw in air and let air out). So what are the implications on the final drive seal.
I concluded that I either need to allow airflow back into the driveshaft by unsealing the boot at the top. Or drill a hole into the driveshaft body to allow water out, and air in.
My bike is due for it's 18000 mile service soon, so I'm going to rip out the shaft again for inspection.
As I've already greased and sealed in the top half of the shaft, so it's airtight.... and then sealed in the bottom half of the shaft, so it's airtight.... I've experienced pressure changes inside the shaft over the past few thousand miles. This has shown itself in the form of either sucking in the bottom boot (under vacuum) or inflating it like a small balloon. I've been manually depressurising it by pressing my bike key onto the boot lip to break the seal.
As this should not be happening, my concerns with this are:-
a) If water gets in, it definitely can't get out. So considerations for moisture/condensation etc.
b) As the shaft heats up, the heat can't escape. So what are the implications on running temps.
c) As the pressure builds (as the shaft moves up and down, it needs to draw in air and let air out). So what are the implications on the final drive seal.
I concluded that I either need to allow airflow back into the driveshaft by unsealing the boot at the top. Or drill a hole into the driveshaft body to allow water out, and air in.
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Maybe just a bit of overthought, but in the video guy says he leaves it open when dry, however if the splines are greased, I would not want anything coming out of the hole and getting on the rear wheel or brakes, maybe overthougt, but this is the wethead section.
I can't remember where that dimple is sighted in relation to the ideal draining position. If it's too high up on the shaft, it won't allow all the water to drain anyway. So I'll have a good look next time and see if it is the ideal place or not.
Deleted account 191119001
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Yeah, I was mentioning and discussing this 'drilling a hole' idea with Beaver (off-here) a while back.
My bike is due for it's 18000 mile service soon, so I'm going to rip out the shaft again for inspection.
As I've already greased and sealed in the top half of the shaft, so it's airtight.... and then sealed in the bottom half of the shaft, so it's airtight.... I've experienced pressure changes inside the shaft over the past few thousand miles. This has shown itself in the form of either sucking in the bottom boot (under vacuum) or inflating it like a small balloon. I've been manually depressurising it by pressing my bike key onto the boot lip to break the seal.
As this should not be happening, my concerns with this are:-
a) If water gets in, it definitely can't get out. So considerations for moisture/condensation etc.
b) As the shaft heats up, the heat can't escape. So what are the implications on running temps.
c) As the pressure builds (as the shaft moves up and down, it needs to draw in air and let air out). So what are the implications on the final drive seal.
I concluded that I either need to allow airflow back into the driveshaft by unsealing the boot at the top. Or drill a hole into the driveshaft body to allow water out, and air in.
Well that bump was obviously designed into the FD for a reason, maybe for the competion bikes to get the water out quick, interesting all of this.
Well that bump was obviously designed into the FD for a reason, maybe for the competion bikes to get the water out quick, interesting all of this.
Don't know
But I don't mind a bit of water getting in, providing it can get back out just as easily and then dry off.
When it's sat there for months sitting and sloshing around in an inch of water..... that's really not good....
It must be frustrating having these issues when many state that a chain-driven bike is a non-starter for them as they want the ease and low maintenance of shaft drive .
Seems to be the complete opposite!
Seems to be the complete opposite!
Delboy777
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Well that bump was obviously designed into the FD for a reason, maybe for the competion bikes to get the water out quick, interesting all of this.
But my dear smog, its not in the final drive
its in the hollow shaft that the drive shaft runs in dear boy 
I'd agree, but only if it bothers you.
Most shaft bikes people will never see it.... and it will never be on their mind to bother with it.... so it isn't maintenance.
It's not on the BMW Service Schedule.... so it just goes unnoticed
>>>> The problem is really for those who intend to keep their bike for a while and don't want this wrecking the final drive splines or sheering off !!
>>>> Or those where the final drive rubber boot has split, and continues to split because it's being sucked onto the shaft knuckle !!
Deleted account 191119001
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Don't know
But I don't mind a bit of water getting in, providing it can get back out just as easily and then dry off.
When it's sat there for months sitting and sloshing around in an inch of water..... that's really not good....
Well blow me down with a feather, just looked under my FD 2017 Exclusive model, and there is a venting grill on both sides of the knobble, and little holes under the knobble alrady, so this would give air and let water out if not full of dust and crap, see below, I wonder if other year bikes before are different.
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