Fix for rusty shaft ? Discuss

[beaver]

I'm 75% sure I'm going down the hole drilling route.... I just can't see any other way.

I'll do it from the inside out though, as the shaft will need to be removed completely to get the optimal drain position (I suspect that circle nobble isn't it)....

I'll probably go with a 6mm (M6) size hole and refit everything. The hole will be primered and painted to prevent corosion and will remain untapped and open. At this point I don't think its so imperative to seal in the rubber boots, unless you want to.

Once I've got the best draining position, you lot can copy the external position and drill from the outside, saving the hassle of having to remove your shaft, and final drive housing.... If you want to copy mine.

I'd suggest you might want to let me test mine for a few thousand miles first to ensure the hole doesn't crack the shaft housing, or anything nasty.

Do you need 6mm?... my 4mm was fine... i drilled from the outdisde in so not sure where it ended up exactly on the inside, but it can't be far off where its required.
I'd be drilling into the circle if you can then its got some thicker support around it....

 

[Engineer]

So ironic , given that you don’t know if there’s a problem with the supposedly maintenance-free shaft drive unless you open it up .
A chain requires very little maintenance but at least you can see a problem developing .

I have never had any need to maintain it, so it’s maintenance free 45,000 miles on my first 1200 GS and an average of 30,000 plus on the rest without any maintenance. Chains on the other hand require constant monitoring and lubrications to ensure reliability and safety, which is fine if you only dick about for a few miles on summer Sundays.

 

[Warlord]

Do you need 6mm?... my 4mm was fine... i drilled from the outdisde in so not sure where it ended up exactly on the inside, but it can't be far off where its required.
I'd be drilling into the circle if you can then its got some thicker support around it....

Yes, but.... you said no water ever drained out of your hole haha

My bike will be on it's centre stand with shaft drive hanging down.

Having seen it all from the inside, the lowest drain point isn't at that circle... it's further down.

Admittedly, when the bike is on it's sidestand the shaft housing is flatter, but then water will be rolling around inside all over the place.

I'm looking for an optimal drain position, or there's no point doing it.

 

[Engineer]

Yes, but.... you said no water ever drained out of your hole haha

My bike will be on it's centre stand with shaft drive hanging down.

Having seen it all from the inside, the lowest drain point isn't at that circle... it's further down.

Admittedly, when the bike is on it's sidestand the shaft housing is flatter, but then water will be rolling around inside all over the place.

I'm looking for an optimal drain position, or there's no point doing it.

Perhaps there isn’t an optimal position for a drain hole, that’s why there isn’t one?

 

[Warlord]

I'm considering 6mm, to allow some room for painting and corrosion resistance.

 

[Warlord]

Perhaps there isn’t an optimal position for a drain hole, that’s why there isn’t one?

But wouldn't you agree, water runs downwards.

The lowest standing point is where water pools.

So thats where the drain hole should be sited?

 

[Warlord]

Jeezus, did I really have to just explain that to an Engineer?

 

[Deleted account 191119001]

Do you need 6mm?... my 4mm was fine... i drilled from the outdisde in so not sure where it ended up exactly on the inside, but it can't be far off where its required.
I'd be drilling into the circle if you can then its got some thicker support around it....

I still find something strange is that them boots are supposed to be hermetically closed so as to not let in any sort of moisture, if a hole was drilled and left open, surely moist air can get inside and start corrosion, and defeats the whole object of the hole simply draining water out, the problem seems to be incorrect seating of the boots either the top or bottom one, until that is not resolved, drilling might weaken the shaft as warlord says, and I can agree the circle seems more solid, but that swingarm takes quite a bashing going up and down on the road, I aint so sure it would be safe to drill it, maybe over worrying.

 

[Deleted account 191119001]

Perhaps there isn’t an optimal position for a drain hole, that’s why there isn’t one?

Simply because the boots are supposed to be hermetically closed, and it seems it is not always the case.

 

[beaver]

well, without a model and stress anaylasis we'll never know the answer in real terms.. but going back to seat of pants engineering, I'd say drilling on the circle it quite safe. No idea of the safety margine used... 3.5 maybe... (or BMW these days... maybe not LOL)
I wanted mine to drain on the move on dry days.. also to let the air circulate a bit so it can dry out... Maybe I never had water come out as non actualy got in... but I did it more as a breather hole....

 

[Mr Bean]

With the right grease on the boot and it fitted correctly none should get in.

 

[Deleted account 191119001]

With the right grease on the boot and it fitted correctly none should get in.

Seriously Einstein.

 

[Deleted account 191119001]

well, without a model and stress anaylasis we'll never know the answer in real terms.. but going back to seat of pants engineering, I'd say drilling on the circle it quite safe. No idea of the safety margine used... 3.5 maybe... (or BMW these days... maybe not LOL)
I wanted mine to drain on the move on dry days.. also to let the air circulate a bit so it can dry out... Maybe I never had water come out as non actualy got in... but I did it more as a breather hole....

I suppose as a breather hole fine as long as a good coating of acf-50 inside maybe, just a thought.

 

[Mr Bean]

Seriously Einstein.

That's funny coming from you...

Isn't the cure to fit it correctly rather than drilling holes in the swing arm?

 

[Deleted account 191119001]

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....

Totally agree, but think beaver might be correct that circle seems to be a bit stronger to drill in, and that screw as has been said before seems quite long, not sure how thick swingarm is in that area, but would not want the shaft rubbing on the screw, and good thorough spray of all the inside of the swingarm and shaft with acf-50 might help also, just thoughts.

 

[Deleted account 191119001]

That's funny coming from you...

Isn't the cure to fit it correctly rather than drilling holes in the swing arm?

Read my other posts, first before sniping in...as I have already said that, but as the guys want to test something, we are looking at best possible ways to do it, the world evolved doing tests.

 

[beaver]

That's funny coming from you...

Isn't the cure to fit it correctly rather than drilling holes in the swing arm?

if you look at post 4 on here, I've put a link to a previous post... when everything is sealed up 100%, you then get issues with the rubber bellows expanding and contracting with internal air pressure... so as I said before, my thoughts were more a breather...
You can get small one way valves so if it got covered in water it would seal up, but then open again to let water, air out... but not sure how long they'd last.
I didn't want to use a screw as I'd not seen where it went inside, for the reasons quoted above... but a small bung is fine for the days when its chucking it down.. and you can keep a few under the seat...
when its dry just pull it out

 

[Warlord]

Isn't the cure to fit it correctly rather than drilling holes in the swing arm?

Yes, but it's not designed to fit correctly... it's a shit design

 

[Deleted account 191119001]

I wonder what all the circles are actually for, are they some kind of backstop......





bilduploader

 

[fred_jb]

But wouldn't you agree, water runs downwards.

The lowest standing point is where water pools.

So thats where the drain hole should be sited?

Even if this drilling point is not in the optimum position, so long as it is left open when the bike is in use, any water will be forced forwards and backwards by acceleration and deceleration, and side to side by leaning into corners, so should find its way out.

If you fitted some sort of spigot, if that's the right word, permanently open and with a short rubber drain tube attached then it is very unlikely that water would get in by this route. However ingress of moist air, subsequently condensing on the inside surfaces when the bike cools, could be an issue.

Seems like this is something which BMW just haven't paid enough attention to.