Broken bolts

[mjoekingz28]

There a few things I'd like to add to my arsenal: changing a clutch, cv axles, drum brakes and Broken bolts. I think broken bolts would be the easiest next process as it only requires what I guess to be minimal steps and minimal tools needed.

A few weeks ago I rounded off the head to a bolt on the exhaust of my dirtbike when trying to service the spark arrestor. I was using a 8mm and got 2 of the 3 bolts out no problem then rounded off the third and found out it was a 5/16. really?, a STD on a metric bike...I still don't understand. Anyway,

Can anyone help me achieve this skill? A few years ago I was changing the thermostat in my Dakota and was really straining on getting one of the bolts out and then it just kept getting easier and easier until it snapped. Me and my friend bought what seems like every drill bit at the hardware store and still had no luck. We had to put it on a trailer and take it to my dad's friend's house and he got it out without damaging the threads as the new bolt went in no problem.

Is this something a simpleton like myself can perform? What are the processes and what tools will I need to get various sized fasteners out after rounded off, head broken and/or seized.

Also, on my exhaust I chewed up the head beyond recognition and grinded it off to get at the spark arrestor. After you snap the head off is there still torque in the threads. What I mean, is do the threads hold the torque or the head of the bolt? thanks

 

[mechtech2]

There are specialty sockets sold that will help a lot with rounded of bolt heads. They bite and grab. Often , even a good flank drive socket will do the trick.

But a real broken bolt can be pure heck to remove. Direct access is often horrible, and a flush broken bolt/stud can be really tight in there. Each case is individually attacked.
Studs are usually very hard, and tough to drill out. Thankfully, there are thread replacement devices like Heli-Coils to fix really messed up threads, afterwards.

 

[bdcardinal]

theres a guy here that will show up to wherever you are and ultrasonically remove any bolts. came in real handy when not only did a cobalt, then a titanium bit broke, but a tap broke, than a broken tap remover broke off also.

 

[TurboLuver]

Funny you should ask, I just broke a valve cover bolt off in the head. What I have is a set of easy outs and a set of quality drill bits. The easy out will generally have the size drill bit you need stamped on it. In this case the bit called for was a 1/8. Drill a hole in the center of the bolt, then use the easy out to back it out.

I also have a couple sets of bolt extractors for rounded off bolt heads.

 

[1993_VG30E_GXE]

Broken fasteners = NIGHTMARE that's all I have to say. I've run in to this problem alot and it either costs money to get out (actually it will always cost money), and major time. Because of access, you may have to do complete engine teardown to get access to that removal. Sometimes a single fastener could render an entire car useless such as the transverse link gussets on the suspension, or the transmission mounts etc. They can be fixed but the cost becomes prohibitive at a certain point I was almost at the point the other night I was going to just buy another chassis instead of bothering to fix the broken bolts. If the weld anchors break off in the thin sheet metal chassis, you've got HUGE problems. I've come to the conclusion that when you start stripping down a 16 yr old car to the bare chassis, removing stuff like the crossmember, your taking major risks.

The problem is stuff was never assembled with anti-seize in the first place and/or over torqued possibly stripped be a previous mechanic. ALWAYS use anti-seize on all the fasteners (except for the head bolts, rocker shaft bolts etc... like internal engine parts that likely call for engine oil. The best anti-seize i've found is Jet-Lube 550, it has a wide service rating for temperature and can be used for the exhaust. Adjust your torque value if lubing the threads. For 550 you multiply the torque by 0.65

So for removal, here's what I've used:
1. Acetelyene air gas to heat it
2. Loctite Solvo-Rust to penetrate it
3. Tap it with a punch to agitate it
4. Try the drill method then Cleveland Ezy-Out, but BE WARNED if you break the easy out inside the bolt, you will be looking at a costly removal, and taking it to a machine shop with a precision drill.
5. If you can hold it steady, a Carbide End Mill or Carbide Burr, the really small ones, but again, these can jump to the side and you'll instantly start taking metal off.

 

[Steve S]

Off topic but high quality 6 point sockets minimum Craftsman are a good investment if you want to play mechanic. I have Snapon tools from my 23 years as a mechanic and good tools make a big difference.

 

[PT1]

I have a set of those bolt extractors. Found them in the closeout bin at Sears for $10 for a set of 10. My favorite tool is the reverse drill bit. Most of the time you start drilling and the heat from the bit backs out the bolt.

 

[andyd]

Patience is the best tool for dealing with a sheared bolt or stud. The thing is to not make the condition worse. I start with a sharp 1/8 bit and work up in size until I can see the threads. Then I pick out the remains with a small punch or something. Usually, I don't need to re-tap.

 

[chrome]

Originally Posted By: mechtech2
There are specialty sockets sold that will help a lot with rounded of bolt heads. They bite and grab.


Metrinch makes them... I have used them on badly rounded bolts/nuts and they almost always grab and loosen them without much issues.

 

[Shannow]

Originally Posted By: andyd
Patience is the best tool for dealing with a sheared bolt or stud. The thing is to not make the condition worse. I start with a sharp 1/8 bit and work up in size until I can see the threads. Then I pick out the remains with a small punch or something. Usually, I don't need to re-tap.


That's what we do with the 5-1/2"UH studs at work when they get stuck in a casing.

 

[Silk]

I use some fancy extractors that drill an anticlock hole....then the extractor part runs down the drill and winds it out.I've found just using a left hand drill bit is enough usually to wind them out.

 

[George7941]

Originally Posted By: mjoekingz28
A few weeks ago I rounded off the head to a bolt on the exhaust of my dirtbike when trying to service the spark arrestor. I was using a 8mm and got 2 of the 3 bolts out no problem then rounded off the third and found out it was a 5/16. really?, a STD on a metric bike...I still don't understand. Anyway,


5/16in = 7.937mm. They are so close that I doubt you had a 5/16 hex head. It was probably a 8mm hex head that was slightly worn/rounded.

 

[Kestas]

Early in my wrenching career the second big tool purchase for me was an oxy-acetylene torch kit just to deal with rusted fasteners.

The first significant tool purchase was a set of 6-pt impact sockets bought 35 years ago and I use to this day.

 

[johnd]

Quote:
Early in my wrenching career the second big tool purchase for me was an oxy-acetylene torch kit just to deal with rusted fasteners.


I can't get anything off an exhaust system without breaking it unless I use heat-manifolds are esp. bad. If you can't afford oxy/act MAP gas will get things hot enough to work. Propane usually will not.

Incidentally, if you use a steel bolt and a brass or stainless nut when you put things together, they can be removed much easier.

 

[swalve]

I have had some success with using a file to clean up the head of a bolt, converting it to the next smaller size. Then heat up the surrounding metal as hot as you can stand, and go for it.

Even for a broken off head, sometimes a little grinding is enough to be able to get a hefty crescent wrench on it and extract it.

If you have to drill it out, I can't offer much advice. I've never had any luck. All I can imagine is that if you are using hand tools, clean up the surface of the stud and use the tiniest drill bit you can find to drill a pilot hole. Then move up to the correct size for an extractor.

 

[1993_VG30E_GXE]

Originally Posted By: johnd
Quote:
Early in my wrenching career the second big tool purchase for me was an oxy-acetylene torch kit just to deal with rusted fasteners.


I can't get anything off an exhaust system without breaking it unless I use heat-manifolds are esp. bad. If you can't afford oxy/act MAP gas will get things hot enough to work. Propane usually will not.

Incidentally, if you use a steel bolt and a brass or stainless nut when you put things together, they can be removed much easier.


I agree - I tried those cheap propane tanks at walmart - and they won't get it cherry red hot. Acetylene gas will. I've never tried the MAPP gas but I heard it can get it red too.

 

[1993_VG30E_GXE]

Also, if it's a stud, like the intake manifold studs that could be stuck or exhaust manifold studs, or the studs in a header pipe, a great way to remove those is to use a MIG to weld hex nuts threaded on a bit to the studs. Then heat the stud with penetrant then back it out.

 

[Trav]

For exhaust manifold nuts i usually go to a German car parts dept.Most use OEM copper nuts in common metric sizes.

For exhaust studs that rot badly like on Ford F150 and Expeditions i torch the head of them first,remove the manifold,heat the remaining stud then use dry ice,small vice grips will spin them right out.

 

[severach]

Originally Posted By: chrome
Metrinch makes them... I have used them on badly rounded bolts/nuts and they almost always grab and loosen them without much issues.

I have some Metrinch equivalents by Benchtop, a long gone K-Mart tool brand name. For worn fasteners that still have their head the Benchtop will turn when the SnapOn slips.