Rear shock bottom bolt
- Thread starter big_kitch
- Start date
Because it's a safety critical fastener and warrants a heightened specification?
It *is* in tension as it clamps the lower shock absorber bush between the inner faces of the swingarm receiving faces. The bolt exerts a clamping force, it doesn't (or at least shouldn't) have to withstand shear forces.
AberdeenAngus
Registered user
Moderate heat and impact driver with well fitting bits.
According to the RepRom CD it should only be tighteneed to 58Nm and use Loctite 243, which is a medium strength lock. I do recall that when I replaced my rear shock I poured boiling water over the swingarm to heat it. Use dit to heat the area around wher the therad in the swing aram is, worked a treat for me.
At only 58 Nm it may be worth first turning in the tightening direction, just to break the bond, then undoing.
At only 58 Nm it may be worth first turning in the tightening direction, just to break the bond, then undoing.
There is a shear load on the bolt where the bush is clamped against the swinging arm. The load applied to the bolt through the shock absorber is at ninety degrees to the centreline of the bolt which makes it a shear load.
Yes, heat it with a hot air gun on the swing arm casting where the female threads are situated for a good half an hour, be sure to keep it swirling about and prevent burning the paint finish. When the swing arm casting is too hot to touch, hammer in the Torx bit then use the breaker bar with an extension pole on the end. After much huffing and puffing with facials a gym bunny would be proud of, you should hear one almighty crack followed by slow undoing of the bastard thing.
If the bush gets stuck in the casting, use some stud bar and nuts/ fat washers to draw it out into an oversize deep socket.
NZRalphy
Registered user
Couple of reply have said LOTS of heat. They are wrong! So wrong it is scary. Loctite on this bolt will give up its hold at about 120-140C...... Just above boiling water! Put heat onto the bolt and wait for a puf of white smoke. By all means use heat and use a flame but be precise, try a micro flame as used in the kitchen for Cheifs.
Knutttt
Registered user
Apply for being late, have just come across this thread, weirdly my rear shock seal went on Monday too, not a great way to start the week.
Bike is with a local mechanic who knows his stuff but has been snowed under this week so a bit of a delay getting started, by the sound of things In glad I didn't try to sort it myself.
My bike is a 58 plate GS1200, brought a couple years ago with 3600 miles showing and was immaculate, now due its 18,000 mile service and this the second big failure I've had (rear bearing failed last year).
Bit saddened really as I'd hoped this bike would be a keeper, will have to see.
Strangely, the seal went getting the bike out of the garage, no oil in the garage but popped it on the centre stand on the drive, went and locked up the garage and the oil was flooding out. :-(
Andy
Bike is with a local mechanic who knows his stuff but has been snowed under this week so a bit of a delay getting started, by the sound of things In glad I didn't try to sort it myself.
My bike is a 58 plate GS1200, brought a couple years ago with 3600 miles showing and was immaculate, now due its 18,000 mile service and this the second big failure I've had (rear bearing failed last year).
Bit saddened really as I'd hoped this bike would be a keeper, will have to see.
Strangely, the seal went getting the bike out of the garage, no oil in the garage but popped it on the centre stand on the drive, went and locked up the garage and the oil was flooding out. :-(
Andy
i think you got the wrong end of the stick matey we are talking about using a hot air gun.a flame is a bad move imo
Thanks for all the advice guys. Your advice encouraged me to persevere. Got my Torx bit replaced free by Halfords. Applied direct heat to the bolt head for about 2 minutes with a plumber's blow torch and hey presto - well chuffed.
Of course the next problem is that I can't shift the bush. Have looked at the parts fiche and can't quite decide if it should be able to slide in/out in either direction? Tried belting it with a mallet but it wasn't going anywhere...
@Pukmeister Can you describe your approach in a bit more detail as I can't quite envisage what you are suggesting?
Thanks again.
Nick
There is no way these bolts are being held on the loctite, it's only a 10mm bolt in aluminium, a long breaker bar would strip the thread or snap the bolt with the amount of force you can apply. It will be corrosion between the bolt head the sliding bush and the swingarm, if mine had been stuck the first thing I would have done (after swearing) would be make up some penetrating fluid by mixing ATF or power steering fluid with acetone, its the best penetrating fluid bar none, dose it a few times over a couple of hours and try again.
Mate, it is some kind of loctite because when out comes out, the fucking stuff is still solid and blue if I remember.
Yes you are correct it does have loctite on it, but I don,t believe this is the problem here, as I said it's only screwed into aluminium, and at a relatively low torque, the loctite is just to stop it coming undone during normal use, not to prevent general maintenance.
I replaced my suspension with Wilbers when the bike was 2 days old and had done only 60 miles. I used a breaker bar and the bolt loosened with an almighty crack then screwed out reluctantly for the first few turns. It was coated in loctite not corrosion. I wrapped an old towel round the swinging arm and poured a couple of kettles of boiling water on it to heat it up first.
Alan R
Yes, but the one in the OP is not coming undone, unlike yours and mine.
bikemad
Registered user
You say you've shifted the bolt the bushing is easy,get a big screwdriver or pry bar between shock & arm (at the base of it) mine was a tight fit got it to budge without too much force,it'll move in any direction.
Yes I take your point. My post was simply to show that even in new condition the bolt takes an unnerving amount of force to loosen. With age and the possible addition of corrosion, which as I reread your post, seems to be the point you were making, the bolt may become extremely difficult to loosen.
Alan R
Thanks. Couldn't get that to work but replacing a rubber mallet with a club hammer to drive it out (towards the centre of the bike) did the trick. Both inside and outside faces have a ring of adherent hard black crap (7 years accumulation of road grime presumably) which must have been preventing it from moving.
Anyway, the whole moral of the tale seems to be that I need to be a bit less of a pussy when wielding the tools!
Thanks for all your suggestions and support. Hopefully the refit will be more straightforward!
Is red Loctite 243 thought to be adequate for the thread of the bottom bolt?
Cheers
Nick
RED is deemed a permanent fixing. BLUE is sufficient on anything you will possibly want to remove again.
Roger.
Roger.
What about the green 270 which is used by BMW?...
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