Rear disc bolts

[pintlicker]

Had a mare of a time last night trying to get my rear disc bolts off    .  I thought they'd be as easy as the fronts, all they seemed to take was a bit of heat and an impact driver and they were off in jig time.  The rears in comparison are ridiculous!  I've first tried using heat and an impact driver and after much whacking of the driver managed to get a small bit of movement on one of them.  Then used a small breaker bar and tried to tease it round and the fucker snapped.  That shouldn't be too much of an issue as I've got access to a drill press and should be able to drill it out.  I started on the others and with a bit of heat managed to get one of them to move a bit but the last thing I want is snap it off as well, it wasn't exactly moving freely.


Anyone got any tips for removing these buggers, at the moment my only plan is to use heat and go slowly?[/size]I've given them a soak overnight in plusgas to see if that helps but i think its the blue loctite that must be causing the issues here so don't think it will help much.  Stuart

[darrsi]

You're not alone!!!
It's caused by the fixed rear disc, compared to the floating discs on the front.
There's a direct heat transfer when breaking that has a bad habit of fusing the bolts to the wheel, and if a heavy duty thread lock was used it just adds to the problem.
I think the main method of success from previous discussions on here is plenty of heat, but I tried that myself, amongst other things, and ended up with just the one bolt half way out before it snapped in half. 
As I needed the bike to stay in service as quickly as possible I quickly decided on buying a used rear wheel and going down that route, rather than spending money trying to get that bolt removed which could still end up being useless if damaged in the process, and also getting a new disc as it was nearing the end of it's limit anyway.

[Jules-C]

Left-handed still bit in press drill and if you're lucky they will start to unscrew themselves when you drilling them out. 

Replace them with stainless ones and don't use the strongest locktite on the planet when you fit them

[joebloggs]

Got mine out with an allen key and mole grips clamped on the head of the bolt. Turn slowly together and take your time.

If thread lock is the major cause of the problem, I'm not sure heat would help, and if its softening the bolt could possibly cause the fastener to shear

As has been said, factory thread lock seems to be the biggest issue.

Not recommending this but I've never used thread lock when re fitting any bolts on a bike, just tightened them up and kept and eye on them.

[pintlicker]

At least its not just me!  I'm not in any big rush to get it sorted at the moment, I'm enjoying the heat of the car in the cold mornings.


I've got a new disc for it so if all else fails then getting a secondhand rim isn't the end of the world, but I'll make sure someone else has removed the disc from it first!  But I'll probably go with more heat and going slow and see if I can get the rest of them out then tackle drilling out the snapped one.  I'm sure I've got a set of L/H drill bits somewhere.


Nothings ever easy! 

[darrsi]

The other issue which adds to the pain is the bolt heads themselves are made from toughened marshmallows, and will round off particularly quickly.

Joebloggs, if you got them off with molegrips then you are one of the lucky ones, 'cos they wouldn't have budged my bolts whatsoever!
And heat "should" soften thread lock.
I only use a very tiny amount of lighter grade threadlock on mine now, and I bought a spare set of bolts to have on hand to replace any that decide to round off in the removal process.
I reckon they dipped the bolts in the strongest threadlock in the world with a sly grin on their face on the assembly line. 

[His Dudeness]

Heat breaks down thread lock and also the expansion and contraction helps to break any corrosion so get the bolt as hot as you can. A soaking in penetrating oil also helps the longer you leave it soaking the better. Also working the bolt in and out helps to break the corrosion around the threads. If you just keep turning it out in one go you can get a build up of corrosion in the threads and then even though you cracked it loose all of a sudden it starts to tighten up again.

[tommyardin]

Had a mare of a time last night trying to get my rear disc bolts off    .  I thought they'd be as easy as the fronts, all they seemed to take was a bit of heat and an impact driver and they were off in jig time.  The rears in comparison are ridiculous!  I've first tried using heat and an impact driver and after much whacking of the driver managed to get a small bit of movement on one of them.  Then used a small breaker bar and tried to tease it round and the fucker snapped.  That shouldn't be too much of an issue as I've got access to a drill press and should be able to drill it out.  I started on the others and with a bit of heat managed to get one of them to move a bit but the last thing I want is snap it off as well, it wasn't exactly moving freely.


Anyone got any tips for removing these buggers, at the moment my only plan is to use heat and go slowly? I've given them a soak overnight in plusgas to see if that helps but i think its the blue loctite that must be causing the issues here so don't think it will help much.  Stuart

Hi I had the same problem when replacing my rear disc.
Some of the problem is that the disc retaining bolts/allen screws protrude through the hub of the wheel into the hollow section of the wheel centre where water and dirt can get, but you can not easily get to to clean that area, the end of the bolts that protrude into that hollow section start to rust, and then a form of electrolysis sets up between the alloy wheel centre and the rusted steel bolts which grips the bolt tight in the alloy and then when you manage to get the bolt to eventually move you are screwing a gnarled up rusted steel bolt through the alloy hub ripping out material as it comes, its not the bolt that suffers but the tapped thread in the alloy.

It took me a couple of hours to get mine out and if my understanding of the problem is right, mine came out reasonably easy compared with some.
I got into my hub with a flexi drive from a dremel with a fine wire brush and cleaned as much of the threads as poss before turning the bolts a quarter of a turn and doing it again and so on untill the bolts had rotated a couple of full turns, sprayed liberally with plus gas release fluid and just kept rocking the bolts back and forth until they eventually came out.
I ran a tapered tap down each bolt hole to ensure the threads were clean using plenty of lube and replaced the bolts with high grade stainless steel bolts, applying plenty HMP grease to the bolts when tightening them up so should they ever need to come out again it should not be a problem.
That was a couple of years ago now I have checked the bolts on 3 or 4 ocassions just to check their tightness because of the HMP grease applied but they have always tight.

Good luck with that but do go gently or you may end up foccing the back wheel by ripping out alloy from the hub and enlarging the holes.
The S/S bolts that I replaced the originals with were a little shorter so they only came flush with the inside of the wheel centre/hub leaving nothing protruding through. 

If you use Stainless Steel bolts do check that they do not foul the rear caliper as the wheel rotates, mine miss the caliper by a 1 mm or two, but it's enough , as I say that was a couple of years ago now and no issues with it   

[pintlicker]

I didn't realise I could get into some of the threads through the wheel.  I probably won't have a chance till the weekend to have another bash at it, but that seems a good idea.  I think I've got one of those flexi attachments on my cheap wee rotary tool that should allow me to get in about it.


Great idea, thanks!