Hey guys,

Unfortunately I snapped a bolt today on the sprocket cover replacing my clutch cable. Those things are so incredibly weak. A few questions:

• Where is the cheapest place I can get just the bolt and not pay through the nose for shipping it?
• How do I extract the broken chunk? On the Bikebandit page it's bolt 21. I've never done an extraction before and could use the advice.
• Is it safe to ride for the following week until I get time to fix it?

Thank you!

1: A local wrecking yard would be my best guess. Or a hardware store for a mis-matched bolt.

2: How far in did it snap? Any bit of it left exposed after the cover is removed?

3: You "might" be ok to ride it, it's tough to say. Only because any time you pull the clutch lever, the mechanism pushes outward on the clutch cover. With a missing bolt, the clutch might not engage fully, or the cover can flex and stress the other bolts. I'd replace it with an Allen head bolt until an original bolt shows up to replace it.

1. No idea for where you live but it is a fairly standard bolt size. Try a big hardware store.

2. a. Can you grab any of the broken bolt with pliers? If so, grab and twist.
b. If the break is uneven, use a small, cheap screwdriver as a chisel and use a hammer to rotate the bolt until you can do a.
c. Use a Dremel or similar to cut a slot that a screwdriver can go into.
d. Ezy-outs which drill and grab the broken bolt so you can get it out. A 6mm bolt is pretty small for that method and I've never had success on bolts this size.


3. I reckon it is. It isn't an oil or water tight cover so nothing should leak or fall off.

Ok is there any bit of the old bolt sticking out of the case? If so get a pair of vice grips and see if it'll wind out. If its broken flush you'll need a small drill and an easy out and a steady hand. If your other bolts are in ok yes you'll be able to ride till you get it fixed. Go down to Walmart or wherever it is you get bolts from and do your best to match the original bolt length keeping in mind the size of the bolt head, make sure it's not too big. Hope that helps

Quote from: Big Rich on August 31, 2013, 06:52:00 PM
1: A local wrecking yard would be my best guess. Or a hardware store for a mis-matched bolt.

2: How far in did it snap? Any bit of it left exposed after the cover is removed?

3: You "might" be ok to ride it, it's tough to say. Only because any time you pull the clutch lever, the mechanism pushes outward on the clutch cover. With a missing bolt, the clutch might not engage fully, or the cover can flex and stress the other bolts. I'd replace it with an Allen head bolt until an original bolt shows up to replace it.

It snapped with MAYBE 1/8 of the threading left. There's not much left in there. It's a very small amount. It's not quite flush with the cover removed. It's maybe a few millimeters behind the recess it sits in. There's still a little bit of threading left on the original bolt. I almost thought about just dealing with it and screwing it back in but I wasn't sure if that was "best practice" for the situation (EDIT: I can't even find the bolt anymore). I don't know how easy it would be to extract the remaining bits considering how small it is. That's what worries me.

I can find a replacement bolt in the mean time if someone can give me the dimensions to it.


Next question:

Do they even make < 6mm left handed drill bits? I'm in a real pickle it seems like because it's broken barely below the surface and I can't access it with anything but a tiny screwdriver or a small drill bit. It didn't break entirely flush but I don't feel the surface left over would be sufficient to force it to turn out (though it really doesn't have much to go). I'm worried the bolt metal isn't strong enough to let a 1/8" carbide left-hand drill bit bite.


EDIT 2: I found the offending bolt. It appears to have quite a bit of thread left on it. Tomorrow I'm going to try to find a left handed drill bit size around 3/16" (just slightly smaller than 6mm) and try to drill it out. There's enough thread on the broken bolt left over (it broke at the threads) that as long as I can drill out the broken part I should be fine to use it until the new one comes in. I gotta call the dealer though - bikebandit has me at $11 and some change for a SINGLE BOLT.

Correct that those cover bolts are fragile and don't need much torque at all.
Which one broke? If far away from the clutch stuff, you are OK. You still might be OK. Let us know which one.
As for the bolt, many of us have boxes of those bolts. Just ask. State what color (black, gray or chrome).

Quote from: adidasguy on August 31, 2013, 11:02:49 PM
Correct that those cover bolts are fragile and don't need much torque at all.
Which one broke? If far away from the clutch stuff, you are OK. You still might be OK. Let us know which one.
As for the bolt, many of us have boxes of those bolts. Just ask. State what color (black, gray or chrome).

Just the man I was hoping to see.




There's an image of it. The bottom-most left bolt.

Gray. If you have a 6x65 bolt that would fit and you could send it to me just name your price and we'll work something out. I'd be forever in your debt.


In your opinion considering the weakness of the crankcase bolts in general, would a 3/16" left hand drill bit get it out if I went extremely slowly?

That one I would say is important - but something you can go without for a short while. After all, it happens that one falls out and the other 4 take do the job. If 2 were broken I'd start to worry.

That one along with the one above it and to the right are the 3 that would do most of the work to hold the cover on against the spring force of the clutch. The 2 on the far right are of lesser importance. Next time, break one of those.

As I've only extracted one broken bolt (an exhaust header bolt on Frank) I can't give the best advice on removing it.
Most likely it will be an easy removal. I'm positive you did not bottom out therefore the bolt should be free to come out.

Some Seafoam-DeepCreep or PB-Blaster in there and some heat to expand the aluminum and it should come out pretty easy.

FYI: I removed the header bolt by drilling a small drill. Then working up one drill size at a time. Eventually the walls of the bolt became so thin that they crumpled up and fell out. You can do that: center pinch in the middle and start with a small drill, working your way up. Be careful when you drill through the bolt: stop right away so you don't drill into the crank case.

PS: You will be OK to ride for a week or more. During that time, send me your address and I'll mail you a  few spare bolts.
Don't worry about 50 cents in postage. Do someone else a favor when they need a part or something.

Quote from: adidasguy on August 31, 2013, 11:38:46 PM
That one I would say is important - but something you can go without for a short while. After all, it happens that one falls out and the other 4 take do the job. If 2 were broken I'd start to worry.

That one along with the one above it and to the right are the 3 that would do most of the work to hold the cover on against the spring force of the clutch. The 2 on the far right are of lesser importance. Next time, break one of those.

As I've only extracted one broken bolt (an exhaust header bolt on Frank) I can't give the best advice on removing it.
Most likely it will be an easy removal. I'm positive you did not bottom out therefore the bolt should be free to come out.

Some Seafoam-DeepCreep or PB-Blaster in there and some heat to expand the aluminum and it should come out pretty easy.

FYI: I removed the header bolt by drilling a small drill. Then working up one drill size at a time. Eventually the walls of the bolt became so thin that they crumpled up and fell out. You can do that: center pinch in the middle and start with a small drill, working your way up. Be careful when you drill through the bolt: stop right away so you don't drill into the crank case.

PS: You will be OK to ride for a week or more. During that time, send me your address and I'll mail you a  few spare bolts.
Don't worry about 50 cents in postage. Do someone else a favor when they need a part or something.

PM sent.

My battle plan tomorrow is start with a 1/8" or 3/16" left hand drill bit and SLOWLY start drilling it out. On the off chance it catches it will be extracted in the process. If not, I'll just size up to the next size and do like you said. Thankfully I think it only broke off a very miniscule portion of it so if push came to shove gently drilling it out completely will probably work great.

I have the old bolt in front of me now. I found it after some digging. It appears to have some of the threads left (about 4-5 if it matters). In the mean time would it be worth it to gently screw that bolt back in just to have something there?

I have this extractor kit from Sears.  I've used it to extract the crappy phillips screws on the GS carbs, among other things.  They're basically double-sided left-hand bits.  You use one end to drill a hole into the bolt, then flip the bit around and use the threaded end to grip the bolt from the inside and extract it.

Half my carb screws were just completely stripped, and the other half were so stuck they broke one of my phillips bits.  But the extractor made short work of them.

http://www.sears.com/craftsman-4-pc-drill-out-power-extractor/p-00952155000P?prdNo=20&blockNo=20&blockType=G20

That extractor kit could work. I'll swing by the sears not far from here tomorrow and see if I can get one. The description says it will work on 3mm - 6mm bolts which is right up my alley.

How and why did it shear?

Is it corroded in there or did you over tighten it?

If its corroded your wasting your time with easy-outs, if its just over tightened and your in with a chance.

Be ready with the helicoil kit, its very very unlikely that you will be able drill it out without damaging the thread in the casing.

Quote from: sledge on September 01, 2013, 01:20:14 AM
How and why did it shear?

Is it corroded in there or did you over tighten it?

If its corroded your wasting your time with easy-outs, if its just over tightened and your in with a chance.

Be ready with the helicoil kit, its very very unlikely that you will be able drill it out without damaging the thread in the casing.

It's definitely not corroded. Aside from some dirt and grime the bolt looks new. I figured its worth a shot to go about it with some left hand drill bits (in particular the extractor kit posted above...) and go as slowly as possible. From some reading on other forums it appears that easy-outs aren't an option. Nearly everywhere I read said that they tend to break in sizes that small. If that doesn't work I'll be paying a mechanic to install a helicoil kit for me at $75 an hour and this will be the most expensive clutch cable replacement I've ever done.


EDIT: It doesn't seem very hard to do the helicoil myself. I just don't know where to find an 8mm helicoil. Off hand would you know which helicoil I would use exactly?

If its not stuck in the threads LH drills and/or easy-outs are worth a shot.

You will need a helicoil to match the bolt, in this case M6x1

Amazon/ebay is loaded with kits..

This is the one I use..... http://www.amazon.co.uk/Clarke-thread-repairing-kit-cht677/dp/B008F54X5U/ref=pd_sim_sbs_diy_2

Instructions are included and they are not difficult to fit, its takes minutes. If you don't have a tap wrench use a small adjustable spanner. Ensure you remove ALL the swarf out of the hole after you have re tapped it and DONT EVER use Loctite on it.

Easy outs can be very effective in some situations but people blindly assume they are the answer to everything.....they are not!

If the fastening is in that tight it has sheared its head it will almost certainly shear an easy out as well.

Quote from: sledge on September 01, 2013, 02:59:45 AM
If its not stuck in the threads LH drills and/or easy-outs are worth a shot.

You will need a helicoil to match the bolt, in this case M6x1

Amazon/ebay is loaded with kits..

This is the one I use..... http://www.amazon.co.uk/Clarke-thread-repairing-kit-cht677/dp/B008F54X5U/ref=pd_sim_sbs_diy_2

Instructions are included and they are not difficult to fit, its takes minutes. If you don't have a tap wrench use a small adjustable spanner. Ensure you remove ALL the swarf out of the hole after you have re tapped it and DONT EVER use Loctite on it.

Easy outs can be very effective in some situations but people blindly assume they are the answer to everything.....they are not!

If the fastening is in that tight it has sheared its head it will almost certainly shear an easy out as well.

Forgot to say how I sheared it. I honestly wish I just sheared the head. If that was the case I would just pull off the cover and vise grip the broken bolt out. It sheared at the threads after over-torquing leaving about 3mm of threads left in the case. Considering how it broke I don't think it's bottomed out.

I should be okay to whack a center punch with a mallet right? I won't damage the crankcase?

Small tap is all it needs for your drill to have a dimple to go in. Have a sharp center pinch and a quick tap or two will do it. You are not pounding nails in a 4x4, so.......

Quote from: Dr.McNinja on September 01, 2013, 10:49:52 AM
It sheared at the threads after over-torquing leaving about 3mm of threads left in the case.

In that case the remnant wont be tight, an easy out may be the best option

Quote from: adidasguy on September 01, 2013, 10:57:22 AM
Small tap is all it needs for your drill to have a dimple to go in. Have a sharp center pinch and a quick tap or two will do it. You are not pounding nails in a 4x4, so.......

Picked up a punch today. Couldn't find a sharp one but I'll just file down this flat one until it's sharp enough. Unfortunately the Sears didn't have the kit I was looking for so I'm going to go shopping at another one to see if I can find either an easy out for that size or a left handed drill bit sized to sub 1/16" (since 1/16" seems kinda large - it's the size of punch I found).


Update -


Ordered

http://www.amazon.com/Alden-1647P-Grabit-Broken-Extractor/dp/B000RPUSFU/ref=sr_1_6?ie=UTF8&qid=1378072253&sr=8-6&keywords=grabit+broken+bolt+extractor


Today since no one in town carried anything I could use believe it or not. Figured this will work great. I'll keep you guys posted on the progress. I'll be doing the extraction this Saturday.

In the mean time, should I spray some penetrant on it and hope it vibrates out while I'm riding? Or will dirty penetrant make the extraction process more difficult?

Bit of penetrant wouldn't hurt

Quote from: slipperymongoose on September 01, 2013, 08:00:39 PM
Bit of penetrant wouldn't hurt

You say that to all the boys Slips. I'm not buying it.