broken hex bolt in clutch

[dontbesojumpy]

Jesus doesnt want me to have a motorbike that works. after getting my fourth clutch (only 2 have ever actually been in the bike to make it go) we have yet another issue. i put in the latest clutch, everything went fine, but i forgot to actuate the pushrod before closing everything up. long story short, a bold broke off down in the hub post. it was a bad bolt, it sheared in the middle as i went to untighten it ( and i tightened to ducati shop manual inch-pounds correctly, too.)

so. i've had trouble getting a tap in to pull it because it's such an uneven break. i started to try to drill for the tap but it slipped and took some threads off the inside of the post. so, deep in the pit of my stomach, something tells me that even if we magically get the broken bolt out, the fact some threads are gone makes this clutch useless. i imagine the tolerances are low so the missing threads weaken that post to the point of uselessness...?

or can this be salvaged.

someone please tell me the "or can this be salvaged" thing...please...

also, ask God why i'm not supposed to have a bike. or tell my ex to knock off the motorcycle voodoo...

[ducpainter]

I think you'll get better responses in tech, so I'm going to move this.

[brad black]

you mean a screw that holds a spring in?

what sort of bike is it - you might be able to get away with 4 springs anyway, solving the issue.

apart from that, i see you having little joy from what you're describing.

[dontbesojumpy]

you mean a screw that holds a spring in?

what sort of bike is it - you might be able to get away with 4 springs anyway, solving the issue.

apart from that, i see you having little joy from what you're describing.

it's an 04 monster dark (620i.e.)

i worry so much because my last clutch failed when three of the six (or however many) posts broke for the springs. the posts BROKE. i guess too much tension or something, or uneven tension. i was thinking of taking it to a machine shop to try to extract it but i dunno. i also thought of drilling it out (probably ruining the threads for the next bolt) but j.b. welding the new bolt seated to the correct spring tension to keep it all afloat.

no. no joy. i left out the part of the story where i bought a clutch used pre-assembled by a mechanic so i didnt have to mess with it and a teensy bolt fell down between hub and basket and cracked the hub before i could even get it on. so i'm buying used clutches like meals lately.

[Ddan]

My redneck engineering solution would be to:

Square up another bolt in the drill press vice and using whatever bit will self-center in the top of the bolt, just put a dimple in the bottom of the hex recess.  Centering a small bit in that dimple, drill down the center of the bolt a fair ways, and cut off the balance.  Thread the drilled piece into the post until it just bottoms out on the remainder of the broken bolt.  Drill into the broken bolt, back out the centering bolt and use a slightly larger left hand bit to pull out the broken bolt.

[dontbesojumpy]

My redneck engineering solution would be to:

Square up another bolt in the drill press vice and using whatever bit will self-center in the top of the bolt, just put a dimple in the bottom of the hex recess.  Centering a small bit in that dimple, drill down the center of the bolt a fair ways, and cut off the balance.  Thread the drilled piece into the post until it just bottoms out on the remainder of the broken bolt.  Drill into the broken bolt, back out the centering bolt and use a slightly larger left hand bit to pull out the broken bolt.

have you ever heard brian regan's bit about UPS and their 'girth formula for boxes?' reminds me of this. just kidding i think you're on to something. i'm going to try again tomorrow.

[johnster]

Those posts, for whatever reason, are VERY brittle. 

It's possible to run a dry clutch with 4 springs and just leave two opposite spring posts empty. I would imagine there shouldn't be any reason wy this wouldn't work on a wet clutch, right? Have you considered that?

[dontbesojumpy]

Those posts, for whatever reason, are VERY brittle. 

It's possible to run a dry clutch with 4 springs and just leave two opposite spring posts empty. I would imagine there shouldn't be any reason wy this wouldn't work on a wet clutch, right? Have you considered that?

again, my last clutch failed when at least one post broke causing a chain reaction of breakage. no one i've talked to have a good ascertation as to what went wrong, but i assume it was too tight springs. one failed the others followed. that seems to be the best explaination.

so i'm really reluctant to skip posts. i'm going to try tomorrow (i hope tomorrow) to jig it up in a press and see what damage i can do.