Its easy enough to unbolt the FD knuckle then slide it rearwards away from the bike complete with driveshaft, it then becomes possible to use a vice to hold the shaft. The vice will act as a heatsink if you choose to use a blowlamp.
Driveshaft Splines Stuck to Pinion
- Thread starter Tomb1988
- Start date
If the fwd / gearbox end has detached, can it not be drawn out of the swing arm with the drive attached.
Then suspend the shaft by the gearbox UJ and strap the drive end through the UJ
apply heat to the main drive /spline cup and wind the strap up to pull the drive (as per Steptoes suggestion)
I'd just do that applying and releasing pressure until it pops
Then suspend the shaft by the gearbox UJ and strap the drive end through the UJ
apply heat to the main drive /spline cup and wind the strap up to pull the drive (as per Steptoes suggestion)
I'd just do that applying and releasing pressure until it pops
Tomb1988
Registered user
Thanks, I will do!
The driveshaft is still in the swing arm attached to the FD. It is the FD I am trying to remove it from, which I was trying to do without removing the FD from the bike. It is looking like I will have to remove it at this point. I thank you for your input, but I just can't quite see how I would get in there. Looks a bit (but not exactly) line this:
Looks like that will be my next move. I understand that the bolt is thread locked and requires a heat gun, I will need to dig this out tomorrow and watch some videos of other people taking the FD off.
My neighbor kindly dropped off a bottle jack today, so I may try something like this (I only have crappy ratchet straps), though not sure if this will cause damage to the pinion bearing.
Failing all else I'll heat the hell out of it and borrow both of my neighbors tractors, FD tied to one and shaft to the other. A little extreme, but you know what its like when you get frustrated with things... That, work and the rain meant I didn't get to do anything today, but tomorrow is another day.
First of all, assuming we are discussing the pivot bolt that holds the swing arm to the final drive.....I can tell you from very, very recent experience that the bolt is definitely thread locked. Lots of BMW red thread lock.
It was one of the hardest fasteners I have ever had to undo. I did it yesterday. It really does require that you get quite a lot of heat into the bolt itself. Heat it, then allow the heat to penetrate, then heat it a bit more. Rinse and repeat until it is good and hot all the way through.
Even then. you will need a good, long 1/2" breaker bar to shift it if it is anything like mine.
I had the bike on the centre stand, put a T50?? socket on the breaker bar and put that on the left hand side. Then I put a 1/2 ratchet with a 24mm?? socket on the right side and rotated everything so the breaker bar was held solid in place by the floor. Then I put a bit of pipe on the ratchet to extend the lever and gave it some welly. It came off after a lot of pressure, and was even then really hard to wind out.
Make sure you use heat and good quality, proper sized tools - or you will end up stripping the fasteners and that will be bad.
EDIT - if you can get a good impact driver into the left hand side with a T50 bit, use lots of heat and brace the 24mm nut on the right against the ground with a bar, then it should come off fairly easily. I think.
Ok, I'm starting to see the picture now. Sorry for my misunderstanding.
Allow me to deliver one more shot (though, probably a blind shot):
You are aware that trying to release the FD from the shaft by simply removing the bolt from the upper link arm and then trying to swing the FD rearwards in order to release the driveshaft from the FD will not work?
In order to release the rear splines from the FD you swing the FD slightly rearwards. Then you push the rubber boot rearwards and force a large screwdriver into the gap between the swingarm and rubber boot and into the gap between U-joint and the shaft (the aim is to find a way to stop the u-joint to slide rearwards). With the screwdriver in place, you lift the FD back up, thereby pushing the U-joint as far forward as possible, and then, holding the shaft compressed (and u-joint as far forward as possible) by the screwdriver, you may now easily remove the FD from the splines.
As long as there is corrosion involved, this is probably not the issue here, but I just had to mention it, since the OP is fairly new to the bike and the procedure is not mentioned in the manuals.
Allow me to deliver one more shot (though, probably a blind shot):
You are aware that trying to release the FD from the shaft by simply removing the bolt from the upper link arm and then trying to swing the FD rearwards in order to release the driveshaft from the FD will not work?
In order to release the rear splines from the FD you swing the FD slightly rearwards. Then you push the rubber boot rearwards and force a large screwdriver into the gap between the swingarm and rubber boot and into the gap between U-joint and the shaft (the aim is to find a way to stop the u-joint to slide rearwards). With the screwdriver in place, you lift the FD back up, thereby pushing the U-joint as far forward as possible, and then, holding the shaft compressed (and u-joint as far forward as possible) by the screwdriver, you may now easily remove the FD from the splines.
As long as there is corrosion involved, this is probably not the issue here, but I just had to mention it, since the OP is fairly new to the bike and the procedure is not mentioned in the manuals.
First of all, assuming we are discussing the pivot bolt that holds the swing arm to the final drive.....I can tell you from very, very recent experience that the bolt is definitely thread locked. Lots of BMW red thread lock.
It was one of the hardest fasteners I have ever had to undo. I did it yesterday. It really does require that you get quite a lot of heat into the bolt itself. Heat it, then allow the heat to penetrate, then heat it a bit more. Rinse and repeat until it is good and hot all the way through.
Even then. you will need a good, long 1/2" breaker bar to shift it if it is anything like mine.
I had the bike on the centre stand, put a T50?? socket on the breaker bar and put that on the left hand side. Then I put a 1/2 ratchet with a 24mm?? socket on the right side and rotated everything so the breaker bar was held solid in place by the floor. Then I put a bit of pipe on the ratchet to extend the lever and gave it some welly. It came off after a lot of pressure, and was even then really hard to wind out.
Make sure you use heat and good quality, proper sized tools - or you will end up stripping the fasteners and that will be bad.
EDIT - if you can get a good impact driver into the left hand side with a T50 bit, use lots of heat and brace the 24mm nut on the right against the ground with a bar, then it should come off fairly easily. I think.
I just put a breaker bar on mine ans turned it. It went eventually
I just put a breaker bar on mine ans turned it. It went eventually
Mine was a total cnut. With very real danger of stripping the fasteners at every point of the journey.
I just put a breaker bar on mine ans turned it. It went eventually
According to the manual, there is no mentioning of warming up during dismantling, however, as it is secured with locktight heating the nut will probably make it easier. The torque for the tightening is 100Nm, so either way, it takes some quality tools and muscles for sure.
The first step of removing the plastic cover may be a bitch if you want no scartch on the cover. The way I do it is that I degrease the cover and the head of a small flatheaded screwdriver, then I use a gluegun and glue the screwdriver to the cover, and pulls it off. The glue is quite easy to remove afterwards.
I've had a few bolts snap on customers bikes over the years. I now keep a bolt and insert on the shelf so o don't get held up if it happens.
Tomb1988
Registered user
Thanks to you all for your input to date, it is much appreciated!
I have managed to reassemble the bike and intend to take it for a few rides now that there is penetrating oil in the splines, in the hope that it frees up a bit. It also means I can move the bike to my dads garage where it'll be easier to get heat where I want it and not be held up by rain etc. Just need to find some bumpy roads!
For anyone who gets as far as I did and wants to get the thing back together:
All that took about 10-15mins with head scratching and hunting for tools.
Can anyone tell me, please, if the driveshaft itself shortens and lengthens, or do the rear splines take up the slight shortening and lengthening of the distance between the gearbox and FD as the swing arm articulates?
Best,
Tom
I have managed to reassemble the bike and intend to take it for a few rides now that there is penetrating oil in the splines, in the hope that it frees up a bit. It also means I can move the bike to my dads garage where it'll be easier to get heat where I want it and not be held up by rain etc. Just need to find some bumpy roads!
For anyone who gets as far as I did and wants to get the thing back together:
- Don't listen to anyone who tells you it can't be done
- Make sure you have got the plastic collars seated properly in the gaiters - I didn't and had to spend ages faffing with the bloody thing
- Find a friend to help you
- Remove the cable tie from the front gaiter and pull it back
- Scratch your head for a while, but remain confident
- Take a long thin (10mm shank) pry bar and feed it up the swing from the FD, underneath the drive shaft - I recommend wrapping the edge of the FD in something, I scratched mine a bit
- With the pry bar lifting the driveshaft, align the UJ at the gearbox end and lift the FD so the splines engage. I found it best to have the bike in gear for this. Obviously you or your friend will have to lift the FD and turn the brake rotor a bit to get the splines lined up.
- Extract the pry bar, then without letting the FD fall too far back and disengaging from the gearbox end, give the FD a sharp upwards tug and the C clip should pop in
All that took about 10-15mins with head scratching and hunting for tools.
Can anyone tell me, please, if the driveshaft itself shortens and lengthens, or do the rear splines take up the slight shortening and lengthening of the distance between the gearbox and FD as the swing arm articulates?
Best,
Tom
IIRC it slides on the splines, the middle bit is rubber bonded rather than being telescopic. I think the geometry of the paralever arm is such that there is little change in effective length of the shaft when the swing arm articulates.
With the chance to fall flat on my face:
My experience is with K12/13, of similar design, but mirrored.
The shaft is in two parts, the front part, which consists of two parts bonded together by rubber for shock absorption, then there is the rear part with the rear splines and rear u-joint. This rear part slides into the forward part by means of splines. And this split of the shaft is what causes the problem when you try to disconnect the FD.
What happens is that when you swing down the FD, the u-joint that is connected to the FD by means of splines and a C-ring will be pulled back and follow the FD. But as the FD swings back and down, there will be an angle in the bend that makes it impossible for the FD to release the splines, and it all locks up.
Pushing the u-joint forward, thereby compressing the two halfs of the driveshaft and keep it there by force will provide a more straight angle between the FD spline and the u-joint and it will be able to slide off, thus releasing the FD from the driveshaft.
The driveshaft have to be split in two halves, allowing it to extend/compress since the geometry of the swingarm changes the distance between the FD and gearbox ever so slightly when the swingarm moves up/down.
I think the only thing that was said couldn’t be done (by me) was fitting a new front gaiter with the shaft still attached to gearbox output shaft ... unless you remove the swing arm
Tomb1988
Registered user
I think the only thing that was said couldn’t be done (by me) was fitting a new front gaiter with the shaft still attached to gearbox output shaft ... unless you remove the swing arm
Steptoe, that was not directed at you or anyone else who has been kind enough to responded to this thread. Nor in fact did I mean it to be a dig at anyone on the internet who said it couldn't be done - which is how it reads now I have looked at it again. I just wanted to sound encouraging in case someone was stuck and read this thread in the future. Mostly because I was under the impression from reading other threads that it was nigh on impossible to do, when in fact it was relatively straight forward.
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