Bikesure_adrianflux

Seized Bolt Anyone?!

Apology not called for, if I managed to remove the nut the bolt will remain seized with no simple method of pulling / drifting, my thinking was taking the head off will enable drifting toward exhaust through access hole in swingarm.
Whichever method proves fruitful it's going to get ugly, spoke with local machine shop and his view is the bolt is effectively "welded" in situ given zero movement.
 
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Oh dear! I get the picture now.
Unfortunately if that's the case it's made worse by the fact that the bolt goes through a silent block bush in the bottom of the shock. That is to say a steel sleeve encased in rubber. Which is going to make things more complicated when it comes to drifting/turning even with the bolt head off.

You're making me feel good and bad in equal measure, as I considered buying that bike a while ago.

I think it's time for a deep breath and rolling up of the sleeves and stripping it out to remove the swinging arm along with the shock. At least it can then parade in front of various specialists.

I would be considering spark erosion at this stage.
Long ago, I met a chap who had spent about 6 times the value of a Tiger Cub, totally restoring it. He'd had to have a bolt of some sort, spark eroded out of a casing.
This literally evaporates a steel fastener out of it's surroundings without any damage to threads or anything.
No idea where you go to get this service, but worth looking.

A hydraulic press would push the bolt out once the head is off, but the jigs and tools to hold the arm and then press through the hole would be quite complicated.

Either that or find that Gynaecologist who wallpapered his hallway through the letterbox? :freak:
 
Thanks, I did have a quick google, suggests nearest spark erosion might be Peterborough.
Edit (further search revealed Witham Essex, 40mins away)
I'm going to hold off till another pair of eyes have a look and see which is the lesser of two evils, first being drill and drift or second, see if that damaged swingarm axle bolt can be coaxed out to facilitate complete removal.
 
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Sorry, I would have responded to this earlier but I was assuming that we were dealing with the later, rod-type rear suspension here and I have no experience of that.
However, looking at your picture, that looks rather like the earlier, hoop-type suspension.
Is that the case ?
 
Ok ... in that case I understand the problem.
I have the same assembly on my bike.
Although its a 750 which had a steel swingarm as standard, I fitted an ally swingarm from an early 900 some years ago.

Some good news, I think .... you say the nut "is now jammed across (its) points in the channel/saddle washer".
I think this must mean that the shank of the bolt has turned slightly in the aluminium bridge pieces of the swingarm and so it follows that it isn't seized absolutely rock solid in there.
Of course it may well still be pretty tight because that's where the galvanic corrosion will have taken place between the steel bolt and the ally swingarm but it must have moved a tad so it can't be rock solid
... the solid seizing must be in the threads of the bolt and the nut.
This means that if you can remove the bolt head you should (hopefully) be able to knock out the remainder of the bolt using a suitable sized drift, as you have suggested.
I would be inclined to agree with your thinking to drill off the bolt head.

I had a closer look and a measure up.
My workshop manual says that the bolt is M10 x 1.5.
According to my tables, the root dia of those threads will be 8.16mm.
If you can drill at that dia (or preferably a tad larger) and slightly beyond any 10mm shoulder that the bolt will almost certainly have, then the bolt head should separate from the threaded portion.
Using a drill of that dia should avoid cutting into the ally, which is to be avoided at all costs
You'll need to keep the drill centralised and parallel for the same reason.
The drill should centre itself fairly well in the damaged hex socket head and the access hole in the swingarm will be a good guide to keeping the it parallel.

I measured that its 80mm from the outer face of the swingarm to the base of the bolt head, so allowing maybe 30mm of drill shank in the chuck plus a bit of clearance you'll need a drill bit at least 120mm long just to reach the base of the bolt head.
You might need a longer than std drill (the official term is "long series").

I would suggest that you aim to give it your very best shot first time.
If the drill is allowed to rub rather than cut it will only make the material tougher .. and its probably fairly tough already.
Beware of cheap drills .. I have seen some that were ground so poorly at the business end that they wouldn't cut butter. Dormer is a reliable brand and HSS (high speed steel) is the proper grade.
Don't run the drill at high speed as that will only increase its tendency to rub rather than cut. A nice (very) slow speed and a heavy feed pressure is best.
Some cutting oil would help too .. Machine mart used to sell it in litre bottles .. but somewhat counter intuitively, even engine oil is better than nothing. Maybe you know some local engineer who can give you a thimble-full. Or if you twist my arm I'll post you a small bottle.

Long series drills are expensive.
Here's an ebay listing where you'll find prices and a table of sizes / lengths.
www.ebay.co.uk/itm/153729537969
But I came across this guy who is selling a NOS Dormer HSS long series drill of 8.5mm dia for under a tenner. I reckon that's a good deal and possibly the perfect size as it should fit down the damaged 8mm hex socket without touching the sides (8mm allen key measures 9.1mm across the points so when your's spun it should have mangled the hole to about 8.5mm or more) giving you immediate purchase on the meat of the bolt as well as good centralisation of the drill.
www.ebay.co.uk/itm/126294754081

continued .......
 
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You may want to consider drilling a smaller dia pilot hole before going in with the 8.5mm drill.
However a long series drill in a small dia might not be rigid enough.
And it might not centralise so well as the 8.5mm.
If you do fancy that, the same guy in the second listing has a 1/8 inch, long-series drill on offer but that might be too flexy.
Maybe a 4.8mm or 5mm drill from the first supplier might be a better bet.
I'll leave you to ponder that.

Note that although I speak as a bit of an engineer I don't guarantee that my suggestions will work.
But if it were my problem, that's the way I would be thinking of approaching it.

Finally, if it all goes wrong and you wreck the swingarm, I recall that Nasher was offering three ally swingarms for sale a while back and he may still have a couple left. I remember there being surprisingly little interest at the time.
http://www.ukmonster.co.uk/monster/showthread.php?t=59456

Hope that helps, even if only to point you in a different direction.
And good luck.

ps.
As an aside, I wasn't aware when I fitted my ally swingarm that the steel channel/saddle washer existed.
My old steel arm didn't have one but obviously it wouldn't need one.
I can't really see the point of it anyway ... it only seems to hinder access to the nut with a ringspanner.
Maybe it was an assembly aid but I can't even fathom that tbh.
Anyway, I fitted mine just using a plain washer and I'd be inclined to recommend that you do the same.
The damn things are possibly no longer available anyway.
For what its worth, I also fitted a washer under the head of the bolt. Dunno whether that's std or not.
 
If it's a standard 'hoop' swingarm then, you should be able to get access for a narrow sawblade from underneath, maybe an air powered reciprocating type would be best?

Of course that entails lying on the floor, cutting upwards or lifting the bike, lying it down on it's side or better yet, removing the swingarm to get it on the bench.

But I still wonder if welding in a long bit into the head of the bolt might work? you'd have something to work on and the heat might help free it...
 
To add, as per Utopia's post mine has no channel/saddle washer under the nut but then I built mine from a frame and swingarm sourced separately so it is not OEM and I have no idea how Ducati did it.

I too have a washer under both nut and bolt head, I have a stainless bolt/nut with plenty of copper grease on the threads to prevent binding plus, I know it's free as it's been off many a time - including a few months back when I replaced the swingarm.
 
I'm with you all the way on drill bit quality Jeff. It seems hard to buy a good twist drill these days unless you get a mortgage out.

I'm not with you on this 8.5mm thread root though. There's no thread under the head.
Only the nut end is threaded, the rest is full 10mm and smooth as it passes through a silent block bush and it ain't good to have the bush portion threaded.

I do agree that an 8.5mm bit would be a good starting point to centre it and take out the bulk. A smaller diameter will just be more likely to snap in long series and much harder to centre in the head.
The final drill has got to be 10 or 10.5mm to take the head off, but luckily a bigger bit will be stronger.

DD; A reciprocating saw would almost certainly end up cutting the swinging arm if attempting to cut the head off, unless there happened to be a thick washer under the head.
You've virtually re-suggested my suggestions made earlier, but regarding cutting the nut.

I'd still advocate taking the arm and shock off if you can.
Remember also that if the arm is in the bike when/if you get to the belting the bolt out stage, that you need to support the bike by the frame and not on a paddock or side stand. As it will just all collapse once the bolt is out.
Pretty sure you'll have to take the rear exhaust pipe out too as I don't think the bolt will come out that way with the pipe in.

This would be a really good way to hold the bike to do this, even if you don't ride with it on.. and cheap enough too.
https://www.ebay.co.uk/itm/14564280...PWxpH2Ej80k2k+q3qnezBKxpo=|tkp:Bk9SR5qEl57OYw
 
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Yep, I should have considered that the bolt would have a long, or indeed very long shoulder.
Dunno how that escaped me to be honest.
Maybe I've got used to sub standard engineering becoming more commonplace over the years.

You would have to be very careful drilling the head off with a 10mm drill though .. any slight error in centring or parallel could easily result in damage to the swingarm as the drill breaks through.

Also, if you're only drilling to the depth of the head, a std length drill might be long enough.
And now that I think of it, maybe some sort of wide collar could be put over the drill to prevent drilling too deep.
Or maybe a shouldered bush with a 10mm bore made to fit the hole in the swingarm and serving a similar purpose.

I'm throwing ideas off the cuff here but its all food for thought, eh ?
 
I often find the need to have a depth gauge on a hand held drill.
I just measure how much drill bit I don't want to use and cut a bit of wood to that length.
Then just drill through the bit of wood. (preferably on the pillar drill to get it square and central.) Then put it over the bit up to the chuck jaws and you've got a precision depth gauge.

Refining that for this application, I reckon a bit of broom handle might fit in the access hole?
So long as it was drilled dead centrally it would be a guide mandrel and depth gauge as you describe.

A little touch of the bit on the ally shouldn't be too bad though, especially if a washer is used under the replacement bolt head.
 
Thanks guys, been tied up on domestic trivia,
Utopia. Much appreciate your kind words, having inspected the nut a little more thoroughly I'm inclined to believe I was mistaken in my earlier ramblings, I don't believe the nut/bolt assy had moved at all, in spite of all my efforts, suspect it was in this situ when I started on it.
As for drilling the head probably worth mentioning it's going to be a high tensile item.
Regret I don't have air tools of any description, have to see what mate brings over to play with.
Edit.
regarding mangled swingarm axle bolt head (adj sprocket) the incorrect sprocket fitment won't have improved this mess! Can see no evidence of chain attacking crankcases tho, so assume damage is down to previous lack of chain adjustment.
 
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Dunno how much help my slightly off beam ramblings were in the end, but at least they furthered the discussion.
And now that I think of it, there is absolutely no guarantee that the access hole in the swingarm is accurately concentric with the bolt in question.
The drill-stop idea still seems worthwhile though.
 
utopia said:
And now that I think of it, there is absolutely no guarantee that the access hole in the swingarm is accurately concentric with the bolt in question.
The drill-stop idea still seems worthwhile though.
Click to expand...

The access hole in mine measures 17.5mm (a 10mm cap head bolt head is 16mm).

Out of curiosity I have just tried a (standard length?) 10mm drill in the hole and when it first touches the head of the 10mm cap head (with washer) it leaves just 35mm of shank protruding from the swingarm (coincidentally about the depth of the chuck of my drill) so, I don't think you'd need to worry too much about drilling too deep if you're just drilling the head off. Plus, there's enough room to drift the bolt out the nut-side if you remove the exhaust downpipe.
 
Success! Well that was a jolly couple of hours.
Initially the drill bit was just skating off the bolt head, suspect potential work hardening from impact gun etc.
Bolt head eventually gave in to firm attention from die grinder and then drill bit although when the bolt head was completely removed it was still not possible to drift out the remnants, using a tool punch and 4lb club hammer, it was decided to continue with the drill and then try drifting again as further drilling progress was made through the bolt.
Eventually the bolt surrendered, drill bit appears to have gone off centre very slightly but the swingarm appears unharmed.

Thanks again all for kind support and suggestions.
 
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