Grab rail woe

[timpitt77]

Hi ladies and gentlemen.

I have a reoccurring problem with the retaining screw for the grab rail on my 1200 working itself loose. Now the problem seems to be that the nut on the inside has had its thread ruined. (can't remember what that's actually called) Not sure if this happened when the top box plate was being fitted or if the weight of the box plus vibration has done it.

Anyway the nut is welded/part of the frame, so not easy to remedy. I'm thinking of cutting it away from the frame and then getting a suitable nut to replace it (but not weld the replacement onto frame).

Does this sound like a plan or a cockup?

 

[timpitt77]

hhmm not so sure you should be cutting things offf...

 

[Roadsweeper]

Hi ladies and gentlemen.

I have a reoccurring problem with the retaining screw for the grab rail on my 1200 working itself loose. Now the problem seems to be that the nut on the inside has had its thread ruined. (can't remember what that's actually called) Not sure if this happened when the top box plate was being fitted or if the weight of the box plus vibration has done it.

Anyway the nut is welded/part of the frame, so not easy to remedy. I'm thinking of cutting it away from the frame and then getting a suitable nut to replace it (but not weld the replacement onto frame).

Does this sound like a plan or a cockup?

. I can not visualise it at the moment but cutting away from the frame sounds a bit drastic. is it a blind hole ( a hole that is closed at the bottom) could you use a longer bolt and a nut and secure beyond the hole.
Option two drill the captive nut welded to the frame and get it re threaded or fit a helicoil. Which is like a spring to replace the thread, the bolt then threads into the internal coil of the spring.

Try putting the bolt in without the wieght of the grab rail and top box if the bolt can be tightened it could be as you state the vibration and leverage is causing it too shake loose. if the bolt is binding you could try to supplement the nuts grip on the bolts thread with thread tape (PTFE) or loctite.

RS

 

[wheelnut]

Threadlock?

 

[timpitt77]

hmm.. seems my wife thinks she is funny

 

[timpitt77]

. I can not visualise it at the moment but cutting away from the frame sounds a bit drastic. is it a blind hole ( a hole that is closed at the bottom) could you use a longer bolt and a nut and secure beyond the hole.
Option two drill the captive nut welded to the frame and get it re threaded or fit a helicoil. Which is like a spring to replace the thread, the bolt then threads into the internal coil of the spring.

Try putting the bolt in without the wieght of the grab rail and top box if the bolt can be tightened it could be as you state the vibration and leverage is causing it too shake loose. if the bolt is binding you could try to supplement the nuts grip on the bolts thread with thread tape (PTFE) or loctite.

RS

I shall take the rack off and have another look tomorrow. I like the idea of a longer bolt and a nut behind the native nut and will find out what a helicoil is. I'd thought about PTFE but wasn't sure if it was used for anything other than plumbing.

Thanks.

 

[ktmmark]

Go to a small independant car garage with the rack removed, Ask them to put an insert in, it will take no time at all to do and will be a proper repair with no damage to the bike
I i was closer i would have done it for free

 

[cafemaestro]

Had exactly the same problem - the plate was always shaking loose no matter how often I torqued the bolt. I mentioned it to the good people at Balderstones when having a service. Bolt was duly treated with threadlock and problem solved.

4000 miles and no loose bolt

Simples!

 

[timpitt77]

I have taken it all apart today and happy to report that I think the nut is fine. Problem is that a third bolt is somewhere along the A3!
It wouldn't have been possible to put a second behind it after all as when you put the cover on you are unable to hold a bolt in place. I guess that is why BMW have welded it into place

Once I get another bolt I shall be using threadlock, PTFE and whatever else I can get my hands on!

 

[timpitt77]

Ok several bolts and threadlock later and the same problem persists. Managed to retrieve a bolt before it deposited itself onto the road and the thread is definitely worn down. Anyway I tried another bolt and then unscrewed it immediately, low and behold the thread was damaged.

So next question is can a nut be re threaded so it doesn't strip the aluminium bolts?

It only gets critical when the weight of the topbox adds to the stress. Other option is to sell topbox and get a tail pack...

 

[Kremmen]

Thread lock will see you right ..... and definitely not PTFE... unless its' leaking

 

[swissrob]

the bolts are not aluminium unless you have replaceed them, if the bolt threads are being damaged then there would also be some resistance when you are inserting the bolt.

use a tap and re thread the holes then use threadlock on the new bolts and you shouldnt have any problems.