Getting snapped off bolt out of hole

[andrewj]

Hi folks - I bought a used Kubota, the last owner somehow snapped off a bolt shaft inside the area where the ROPS is mounted. It now has 5 bolts instead of 6 holding it on. I feel it is secure, but I want it fixed.

How do I get the threaded shaft out of the hole without boring it larger? Thanks.

 

[carpenter383]

You can try an easy out, you drill a hole in the center of the bolt, then use the tapered drill bit looking thing which has left handed threads to back it out. Or you can try this...drill a hole in a peice of flat steel a little smaller than the broken bolt hold the hole over the broken bolt and weld the flat peice to the broken bolt through the hole. If possible make the flat piece of steel long enough to leave a handle for turning the bolt. The heat from the weld will help break the bolt loose. I have heated rusty bolts up with atorch, then quicly pour cold water on them too, this helps break up the rust.

 

[Willl]

If I have to drill it, I use a LH drill bit and sometimes don't even need the easy-out.

 

[gc2310]

Do yourself a big favour and don't use a tapered easyout. If you are going to try that method, use splined extractors made by Rigid [ also available from Snap-On]. Best way is to drill out to tap size and then run a reverse spiral tap in to pick out what's left. NOTE; you have to drill dead centre. Good luck.

 

[2manyrocks]

Look at the remaining bolts to see what hardness grade you are dealing with. My guess is that this is a pretty hard bolt.

If you want to try the welding method suggested, you may want to apply a good quality penetrating oil to the bolt after you've made a solid weld.

 

[Sherweld]

You can try an easy out, you drill a hole in the center of the bolt, then use the tapered drill bit looking thing which has left handed threads to back it out. Or you can try this...drill a hole in a peice of flat steel a little smaller than the broken bolt hold the hole over the broken bolt and weld the flat peice to the broken bolt through the hole. If possible make the flat piece of steel long enough to leave a handle for turning the bolt. The heat from the weld will help break the bolt loose. I have heated rusty bolts up with atorch, then quicly pour cold water on them too, this helps break up the rust.

The above solution works very well for me, although instead of a flat with a hole, I weld the largest nut whose hole is smaller than the broken part. This allows a choice of wrenches, plus the heat of welding usually does a pretty good job of loosening the broken part.

Sherweld

 

[JoeL4330]

if there is the least bit of bolt exposed, before I tried anything else, I would use a small cold chisel and hit it counter-clockwiseat the periphery ...penetrating oil/liquid wrench, etc. too ...The chisel blade has to be quite small (bolt radius or smaller) and or tilted slightly to only engage a corner of the chisel. Lots of little, persistent taps.

 

[zzvyb6]

Try removing a few of the other bolts in the mount to see how snug they are. If they are loose, then the chisel or star bit will work fastest(best). If snug, the a small drill and an easy out is best (cheapest). The end of a file or concrete nail works too, depending what you have laying around the garage. The problem you will have is that the boken stub will not lend itself to a centered pilot and a regular drill will try to move it inward. However, some of the stuff being posted that you need to buy will NEVER be needed again, so keep your purchase tactics in mind for this. Another method I've used is to stuff a live welding rod in there and have it fuse to the bolt. The heat and the steel is enough to back it out. Oh yeah, there will be some sputter in there, but its faster that fixturing your tractor up in a mill, lathe or drill press, boring out the bolt .0001" undersize and chasing the threads with a 17mm metric tap. As I read it, this is a cosmetic issue more than a safety issue. If this was a cylinder head bolt, maybe a more serious problem. The probability of you actually laying the tractor over on its roof times the side you choose to roll with, divided by the remaining bolt attachment strength is a pretty small number.

 

[Travelover]

If I have to drill it, I use a LH drill bit and sometimes don't even need the easy-out.

I'd second the left hand drill. Harbor Freight has a set that is pretty inexpensive. As noted, often the heat and vibration of drilling makes the bolt come out by itself.

 

[JoeL4330]

Try removing a few of the other bolts in the mount to see how snug they are. If they are loose, then the chisel or star bit will work fastest(best). .

never thought about star drill ...mounted in drill, in reverse?

those who advocate drill bit (reverse or otherwise) are certainly better machinists than I, unless it is somthing I can bring to the drill press or mill ...a portable drill has never worked for me on a hard bolt ... now, maybe if I had a magnetic drill, hmmmm

 

[EddieWalker]

When drilling the hole, make sure you are dead center. Drill the biggest hole you can without ruining the threads. For some holes, I have to drill a pilot hole, then the bigger one.

The reason for the biggest hole possible is so that you can fit the biggest easy out possible into the hole. They will break off on you from time to time and then it just gets to be allot more fun dealing with getting the broken off easy out, out of the hole.

Good luck,
Eddie

 

[john_bud]

The obvious things have been stated. Some tips are

1) soak it with quality penetrent. I use stuff called "Heat pipe lubricant and rust remover" from GM. It's what the mechanics use to get loose stuck bolts and they don't have time to monkey around.

2) Heat the surrounding area as hot as possible. You may burn the paint. Use either a heat gun, propane torch or O/AC. I'm out of O/Ac currently and have been using the HF heat gun with decent success recently.


jb

 

[dodge man]

There is a kit made called a helicoil, that will replace the stock bolt threads with an insert that goes back to stock threads. If its a larger bolt, the kit will be expensive, but they work great. Its kind of a last resort if nothing else works.

 

[dqdave1]

Left handed drill bits are the easiest way to remove the bolt; If broken bolt can be ground flat; that is a plus. Try to center punch broken bolt as close to center as possible. You will have to drill it anyway. Use a left handed drill bit and you may just get it to back out. Easyouts never work. If you break it off; you are up a creek without a paddle.

 

[firemanpat2910]

all the above are good suggestions. I can only add take all the weight, and/or pressure off the bolt before working on it. I have seen bolts that once the head has popped off there is no "load" left on it and they can be unscrewed with an awl. if you can remove surrounding parts, lube it with PB Blaster, smack around part with big hammer to vibrate the PB Blaster in then have at it.

 

[Kays Supply]

All the above is good. I have been working on Grey market versions of these for a while. Most of the bolts will come out easy if you can just get a hold on them. It will be a pain, but taking the ROPS off might give you enough meat left exposed on the bolt to take out with a set of vise grips. I use a Dremel tool to cut a scew driver slot in the top of the broken bolt and then do all the above, heat, lube, shock, and remove. I really like PB Blaster. If you apply it over and over a period of time usually after a day or so the bolt/stud will come right out. Also, if possible it is sometimes easier to screw the bolt on in out the bottom if it can do that. Have you looked to see if some bolt threads are exposed under the fender?

 

[kthompson]

Sitting here trying to think of the ROP mount on my Kubotas and then not knowing the model or your's have no idea if they are the same or not; but can you remove the ROPS and get access to the bolt?

If not or you feel too much effort to begin with, I would use the penetrating oil, then left hand drill bit and if that did not work with heat use the easy out. If an easy out breaks and they do, the only way I have ever seen them taken out was with torch or hammer and punch busting them into little pieces as they are harden steel.

 

[KennyV]

This is the best way if you must remove a broken fixture, bolt stud, tap or bit... metal disintegrators.
Electro Arc Manufacturing Company
These are impresive and a good machiene shop will have a portable unit... KennyV

 

[Jeepnford]

If you take the ROPS off and there's some bolt sticking out,weld a nut to it. If you have a welder anyway.

 

[tomb700]

Andrew, I've had many years success with the following:

Spray the broken bolt with PB penetrating catalyst and let sit for 1 hour, respray.
Blaster, 5 OZ PB Penetrating Catalyst, Penetrates, Lubr

Hit the broken bolt with a flat punch to make the center flat.
Use a center punch and make a generous dimple in the center of the bolt. If you're off a little it's ok....just means the drill can't be so big.

Using a SHARP drill that's about 3/4 the diameter of the broken bolt, drill a hole in the center of the bolt about 1/2 to 1 inch deep. The optimum is to drill completely through the bolt. This releases the outward pressure the bolt has on the threads, i.e. the bolt center is weakened.
I have best success with KD screw extractors that have straight flutes not reverse spirals. For me, the reverse spiral ones just chew up the bolt and act like a drill.
Screw and Bolt Extractors
To use the KD extractors you tap them in hard and back out the bolt using the square head.
If it won't come out easily, use more blaster. It'll work.