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Repairing damaged threaded hole?
coozer - 14/5/17 at 05:41 PM

I have here the swingarm off my twin shock Suzuki Beamish...

This is the stud that the rear shock slips onto and should be secured with an m6 bolt and penny washer..

The thread has stripped and in the past someone has run a drill right through to bolt the shock on..

The hole runs through at an angle as if the drill bit bent as it was going through...



From the back side...



Now, what I was thinking of doing was filling the hole with my mig, clamping the bit to my drill press and drilling a new hole and tapping it...

Couple of things, the welding is bound to leave voids and maybe be too hard??

Also as you can see the thing is chromed...

Any better ideas anyone??

Ta,
Steve


mark chandler - 14/5/17 at 06:03 PM

Try and make a jig so you can drill it straight, open the hole up a couple of sizes then wind in a bigger bolt and tap and drill this to the correct size.

If it's a hollow frame then tap an drill a bit of stock, drill the whole shambles out and weld in the new bit of what is now internally thread bar.

Not much you can do about the chrome.


britishtrident - 14/5/17 at 06:04 PM

M6 ? dosen't sound right for the purpose If I was repairing it I would dril a big hole and weld in a steel bush, in reality I would buy a new part.


r1_pete - 14/5/17 at 06:06 PM

I think you'll do more harm than good trying to centre the hole, how about putting an m6 bolt through and welding the head to the inside of the arm??


owelly - 14/5/17 at 07:03 PM

Weld it and redrill and tap, or drill it a larger size, tap it to suit then redrill and tap correct size.
If you use mild steel welding wire, you'll drill and tap it with no problems.


coozer - 14/5/17 at 07:14 PM

Thanks, what I was going to do was take it out and make a new one on my lathe but I've sold it and now need it again... DOH!


trextr7monkey - 14/5/17 at 08:01 PM

Bring it over you can use one of ours. I should be over next weekend to visit my father so we can maybe get it sorted as I am backwards and forwards quite a lot since he had the fire
Atb
Mike


big-vee-twin - 14/5/17 at 09:13 PM

It looks like a bush is welded in there already, I would grind off the weld remove it and fit a new one.


nick205 - 15/5/17 at 07:53 AM

Observations...

1. It's been repaired quite badly already so doing it again may well make it worse!

2. M6 doesn't sound big enough to secure a shock - I'd have thought M10/M12 or even 1/2"

3. Chromed - you'll have to strip the Chrome away to weld to it anyway. Short of having the finished part re-Chromed I can't see what else you'd do about that. Paint or even powder coat might help, but I'd imagine the part gets a good battering from road grime/salt/water etc.

4. If you can get one how much is a replacement part? Sometimes it's best to replace and move on.


pewe - 15/5/17 at 09:37 AM

You sure it's chromed? I think mine's nickel plated - just in case that makes a difference.
As suggested above I'd be inclined to drill out oversize, weld in a new bush and re-tap.
If it was good enough for Beamish then should be good enough now.
Isn't there a company somewhere around Leeds/Sheffield which holds the parts or is that a brain fart on my part?
Cheers, Pewe10


coozer - 15/5/17 at 10:11 AM

It's a 1976 suzuki Beamish trials bike with a English white hawk chromed frame conversion...

Got a quote to rechrome just the arm... £380... frame needs a little repair as well and rechroming the lot is way above the value of the bike...

There are no new parts available from white hawk, they are long gone....

Crooks suzuki in Barrow have all the suzuki parts in stock but not any of the British conversion parts..


ianhurley20 - 15/5/17 at 03:32 PM

You can now get a powder coat that looks like chrome and is much cheaper



quote:
Originally posted by coozer
It's a 1976 suzuki Beamish trials bike with a English white hawk chromed frame conversion...

Got a quote to rechrome just the arm... £380... frame needs a little repair as well and rechroming the lot is way above the value of the bike...

There are no new parts available from white hawk, they are long gone....

Crooks suzuki in Barrow have all the suzuki parts in stock but not any of the British conversion parts..


MikeRJ - 15/5/17 at 04:26 PM

quote:
Originally posted by nick205
1. It's been repaired quite badly already so doing it again may well make it worse!



That depends on how it's repaired. Drilling out the entire stud/spigot (see below) and welding in a new one should be fine.

quote:
Originally posted by nick205
2. M6 doesn't sound big enough to secure a shock - I'd have thought M10/M12 or even 1/2"



I'm assuming that the shock mounts onto a 10-12mm plain 'spigot' which has a threaded 6mm hole in the end. The M6 bolt would purely stop the shock working off the end of the spigot, it wouldn't take any of the actual suspension forces.

It would be pretty simple to make a replacement and weld it in place, though the job is made more difficult/expensive by the chrome finish.