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Seized Bolt Anyone?!

W

WAH

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Jan 24, 2024
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47
Location
Burnham on Crouch
Bike
Other Ducati
Yes, I know, not very “technical” but beggars can’t be choosers etc.

Monster 900sie resurrection is underway, poor old thing is in a bit of a state, started taking bits off to clean / lube etc. The rear shock being very poor but has proved most unwilling to be removed, specifically the lower 10mm mounting bolt passing through the alloy swingarm and the lock nut sits in a very handy saddle washer that prevents proper attention.
Suspect galvanic corrosion maybe an issue so I had to go all out medieval with heat, cocktail of penetrating fluids, impact gun (240v 450nm) breaker bar with scaffold tube attachment and still no joy to be found. It’s the old issue of trying to decorate the hallway through the letterbox.

Before I dive into yet another rabbit hole and attempt to remove swingarm (those exhaust studs don’t look healthy!) with shock still attached, just wondered if anyone here had suffered a similar fate and successfully resolved issue.
Cheers.
 
I once spent a frustrating few hours removing an almost inaccesible nut on a honda.
I had to use a very tiny chisel with a 5mm cutting edge to get at the nut, split it after an hours wacking.

You don't know anyone with an induction heater or an arc welder? Often really a really brutal heating is needed, you want to be seeing the offending nut go a dull cherry red.
 
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Thanks Nickj, a younger me would have definitely had the burning gear to it by now!
I didn't want to get too physical with it as I don't think the alloy swingarm will take it, another issue with heating being the proximity of the Ohlins (nylon) rebound adjuster and the heatsink nature of the parent material.
Time is on my side I'm not in rush.
 
Timely question; I was musing about the same problem - need to upgrade the shock spring on my 900Sie, and pretty sure that this lower bolt might be just as annoying as the one on my S4 that I eventually just got Moto Rapido to deal with.

Took them over a week, after everything else was done. I asked them what the trick was - they said a combination of heat, judicious use of impact (in both directions) and leaving the penetrating oil to soak between bouts.

It's my impression that many of the factory fasteners may have been assembled completely dry (as were, apparently, the headrace bearings in my 900 Dark)... So if they can be quite tedious if they're exposed and have never been disturbed.

Another favorite are those mushroom head bolts on the rear hugger that rust and look like garbage - and promptly snap off with the tiniest amount of force when you attempt to remove them...
 
I was looking at that bolt, or more specifically the nut, the other day.
I was wondering what to do if it seized. It's a compete bastard though!
My best idea would be to try a reciprocating saw of some sort and try to split the nut with that, splitting the end of the bolt at the same time obviously.

Flames would seem like a bad idea, but I wonder if it would be possible to apply some kind of induction heat to the nut and bolt only?
My first thought about how to do that would involve a stick welder, but could get dodgy!
I've seen a spanner dissolved in seconds when it shorted across a lorry's 24V batteries, so there's a thought, but could get dangerous! The spanner mentioned branded the guy's hand before he could let go of it. (He deserved it to be honest!!)
I reckon a dab on each end of the bolt with 24V jump leads would scare the life out of it!.. :idea:

My bolt was out less than a couple of years ago when the shock was serviced and I'm just hoping that I applied my routine moly grease to the threads.
Might have the swinging arm out soon, so that'll be a good time to replace the bolt and nut with Ti and Moly.

Good luck with the horrible thing mate, and don't hurt yourself!
 
Thanks guys appreciate the support, it's going v slowly and I've bitten the bullet on the ultra (expensive?) penetrating fluid, if that fails then it'll be time to get creative.
There's plenty to do in the meantime, had the tank filler off and the bike has obviously stood a while on its sidestand, luckily it only had a small amount of fuel in it. I say fuel but I can't swear to it, nasty rusty brown yuck with zero odour.
Tis the bike that keeps giving.
 
WAH said:
Thanks Nickj, a younger me would have definitely had the burning gear to it by now!
I didn't want to get too physical with it as I don't think the alloy swingarm will take it, another issue with heating being the proximity of the Ohlins (nylon) rebound adjuster and the heatsink nature of the parent material.
Time is on my side I'm not in rush.
Click to expand...

This could be worth looking at - AdriansModelAeroEngines.com (Technical Topics, loosening rusted nuts and bolts) - an American machinist magazine did an experiment comparing a range of penetrating fluids and found that a home brewed potion consisting of equal parts Automatic Transmission Fluid and Acetone performed much better that any commercial product. They compared the torque required to loosen a batch of corroded fixings after being treated with the different products. You could use cellulose thinners instead of acetone.

Good luck! Martin
 
^^^ I agree, 50% Acetone and 50% diesel is also outstanding. Dosing the offending part daily for a few days usually works for me
 
You got to be real careful with that bottom shock bolt 'cos it's captive in the swingarm. If it starts spinning you're in a world of bad.
 
On a 900Sie the bolt has to be turned several times anti-clockwise to remove it, then it comes right out and can be replaced or renewed.
The nut is stopped from turning by locating in a slot in the swinging arm which is lined with a snug fitting steel channel, fitting both the slot and nut. neither are attached to the swinging arm and fall out once the bolt is removed, so not sure how the bolt is "captive" as such?

Be careful of paintwork and other soluble parts with Acetone. It dissolves most things, some quite quickly.

Maybe time to try the rattle gun again. I find very short blasts to work best with those. The first hit is the one that does the trick in most cases. Holding the trigger relentlessly doesn't seem to achieve much!
 
^ agree with your observations, I'm getting to stage where I'm having to ration the use of the imapact gun, it's rounding off the hex and soon the bit won't fit. Still waiting for the wizards **** to arrive (Innotec) that will be the decision point on what happens next.
The swingarm removal is going to put up a fight too, the spindle bolt adjacent to the output shaft has been mangled by the chain, judging by the scars on it I'd have to guess the chain has come off it under load.
Once again thanks for all the input, it's keeping me sane.
 
I'm currently restoring an old Land Rover and, as such have experienced pretty much every type of seized bolt available, most of which I have just cut out because there's no real alternative and I'll be replacing them anyway.

But a few, where they are in 'sensitive' areas such as aluminium of gearbox housing etc. have required a little more of a sophisticated approach and I've resorted to drilling or drilling then slitting through the bolt, to welding a nut on to a stud or broken bolt, giving something to grip on but, also getting some serious heat into the thing that can help release it and this seems to (mostly) work reasonably well as the weld won't stick to the ally but will heat it up quickly which can help break the bond.

Not sure exactly how the sie swingarm is? but maybe, access depending, you can weld an allen key (ideally one with a socket attachment on the other end) into the head of the bolt so that you can get some proper leverage on it without rounding the bolt head, the heat may then help release it?
 
WAH said:
^ agree with your observations, I'm getting to stage where I'm having to ration the use of the imapact gun, it's rounding off the hex and soon the bit won't fit. Still waiting for the wizards **** to arrive (Innotec) that will be the decision point on what happens next.
The swingarm removal is going to put up a fight too, the spindle bolt adjacent to the output shaft has been mangled by the chain, judging by the scars on it I'd have to guess the chain has come off it under load.
Once again thanks for all the input, it's keeping me sane.
Click to expand...

How about looking for some plastic tube that can be pushed over the nut - then fill the tube with your favoured penetrating fluid and leave for it to do it's stuff?
 
Thanks again guys, the nut is going nowhere, it's now jammed across points in the saddle / channel washer, so much so that it has deformed the washer, the 8mm allen impact bit came from Laser, suspect being long enough to reach may also have been a weakness, in that the tool bit was probably twisting under the torque of the impact gun and not delivering the full effect.
Gave everything a good drink with the Innotec yesterday and will attempt impact gun later today.
Cheers all.
 
update, regret to advise the troublesome hex bolt is no longer a hex bolt! It took a handful of blasts from the impact gun and it rounded off to the point where the tool now just spins uselessly, bugger!
New plan B involves old mate still in the trade with a plethora of plant, so let’s see what two old plater / boilermaker heads can come up with, possibly drill the head off and drift out the remnants, a play-date is pencilled in over the Easter weekend which means Mrs WAH might actually get her list of “Man chores” addressed in the meantime.
I’ll keep you posted on any developments.
Cheers.
Edit:
Image from rear of bike, Allen access through swingarm on the right.
 
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I'm troubled, because it's not a hex bolt and you've showed a picture of a very slightly rounded hex NUT.
The head of the bolt is Allen and is on the left side of the bike.
You reach this with a long extension though the hole in the swinging arm.
It's the bolt that should be turned as the nut is (was?) held by it's flats in the steel channel.
This is because it's virtually impossible to get a tool onto the nut.

If I've got this completely wrong and you have indeed been turning the bolt with an Allen bit, then apologies.
In that case I think the way forward would be to remove the rear exhaust pipe and see if you can get a reciprocating saw with a metal cutting blade, underneath and make a vertical cut through the nut and the end of the bolt. It won't matter too much if you also cut the channel a bit as all three bits are replaceable.

A jigsaw might be the best tool as the builders reciprocating saws are rather long from what I've seen.
 
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