Broken bolt removal, what works for you?

My ratty 1955 IH farm tractor has some broken bolts I need to get out. They are in solid cast iron, 1/2" bolts, they hold the bell crank that lifts the three point hitch. There are 5 out of 6 broken off, 3 flush and two about 1" down in the hole. According to the head markings, they are grade 5 bolts. The section they are in is heavy cast iron on the top of the rear axle, and it's not removable, it's the entire rear section of the tractor. I can't use the three point until I get these out and replaced with some grade 8 bolts.

I know there is a stick welding rod that's not supposed to stick to the cast that I might be able to use to weld a nut to the flush broken ones. I know also that I may have to drill the ones out that are broke below the surface, just not sure what size bit to start with. May be able to use one of those left handed bits for the final hole, figure a 1/2" lefty will be pricey. I don't have a torch, so that's out of the question. These bolts have about 1" to 1.5" of threads judging from the one that wasn't broken.

I've also heard about letting hot candle wax wick in to help with removal, will probably try that on the flush broken ones. These bolts have been in since 1955, but luckily not in a area subject to heat like a engine block or head, but they are on top, so 60 years of rain has soaked in, rusting them tight I'm sure.

So, what do you guys recommend? It's gonna be a bioitch anyway I do it, I know, but I have to get these bolts out, at least 4 of the 5. So, fire away with suggestions! [cl

Ive seen people weld the center of a big washer on the top then weld a big nut to the washer ,, I guess after you do all that welding it gets the bolt hot enough to turn loose ... worst that could happen is the weld brakes loose .. it needs to be a thick washer for good penetration

If you end up drilling them out - use a 13/32 or smaller. 1/2" will take out the threads. Sometimes once you get a hole that is close to the minor diameter you can use a sharp center punch to collapse the rest of the bolt into the middle.

Drilling is problematic because it is difficult to get the hole centered on the bolt. Drill guides help. On the ones that are 1" deep you could make or buy a bushing that is 27/64 OD (or the ID of the hole) and 3/16 ID (or what ever size pilot hole you want). Drill the pilot hole and keep increasing the drill size until you get to the tap drill diameter or until you can get an Easy-Out to bite.

It is possible that putting penetrant in the holes every day for about a week then drilling in the center with a left handed drill will get some of them out.

I have used every kind of penetrant I could find, usually without positive results. Heat seems to be the most reliable - but it usually works best on nuts - hard to heat all that cast iron hot enough to make much difference.

What works best for me? Persistance

PB blaster has been good to me , I dont know how that would work on a bolt thats on the side though

Try a left hand drill bit. I've used them and they work for me. A quick search on the web will tell you more than I can. Good luck.

My 2 cents.
I have done everything listed on the previous posts to remove busted off bolts and have had varying degrees of success with all of them. Sometimes it take a combination of a couple of different techniques.
The one thing that I found is if you weld a washer/nut on top of the bolt try drilling a hole into the bolt a little ways first for the best penetration.
Good luck.
Torchie

Try Freeze-Off. I think BobW mentioned it once. Might work better than heat in this instance?

Thanks for the suggestions, keep'em coming!

Borrow a torch, drill it out, heat it up, then easy out it. Gonna have to use heat of some sort.

Had a similar problem on a Fergy tractor

ended up soaking heaps of wd40 into all the threads

I hammered flat on the heads of bolts to loosen the grip of the rust.
A bit more wd40 and they screwed out

then came hard part, I drilled into the centres of the broken shafts and used ezyouts to remove the broken shafts

then I ran a tap into the rusty threads to clean them up and fitted new bolts

You can just drill them out then use a helicoil to fix the threads.
I would just drill them out, tap the hole to 5/8 and be done with it.

I soaked them with PB Blaster before I left last night, am going to keep doing that every day this week. Got to get a few good bits and a couple of those welding rods.

Cutting oil will be your friend on this job.

I agree with all of these suggestions. 60% of the time, they work every time.

May make up a mixture of acetone and ATF, heard that works real good. Anybody know the ratio of acetone to ATF?

Extractalloy (I think that's how it's spelled) is the rod that can be welded down in a hole, and brought up past the surface so you can get a hold of it with vise-grips. It's like building a tower of weld, once you get it up where you can get at it, work it back and forth. It work hardens real fast and gets tough enough that it resists breaking off. The heat from the weld generally loosens up the thread enough to get it to let go and screw out the first time. I don't know who sells it in the States, we used to have a salesman come around and we got it from him. Worked pretty slick, welds to steel but won't stick to cast.

Sniper said:

Extractalloy (I think that's how it's spelled) is the rod that can be welded down in a hole, and brought up past the surface so you can get a hold of it with vise-grips. It's like building a tower of weld, once you get it up where you can get at it, work it back and forth. It work hardens real fast and gets tough enough that it resists breaking off. The heat from the weld generally loosens up the thread enough to get it to let go and screw out the first time. I don't know who sells it in the States, we used to have a salesman come around and we got it from him. Worked pretty slick, welds to steel but won't stick to cast.

Click to expand...

I haven't heard of that. It sounds pretty slick. If it doesn't get the screw out, can you drill it?

here's link:
https://www.youtube.com/watch?v=L4zohssWS7I

Sorry for the long delay in answering, didn't realize you had a follow up question. That's the same stuff, never went with the added washer and nut though. We were told to just build a "weld tower" and clamp on to that. I have broken off the tower a couple of times but just re-welded it up again and turned it out. We used it a lot on air cooled Wisconsin engines. The head bolts would seize up and break flush or just under the block surface. These rods saved our butt many a time. Never seemed to bother the threads in the cast blocks. I doubt you could drill it, it really work hardens.

I haven't upgraded this because I haven't done anything yet......
I did get some thick washers and nuts, and got 8 of those special welding rods. I hope to start on it tomorrow.

One other thing I screwed up, I somehow broke the end off of the hydraulic cylinder. It had threads on the end, and screwed into a horseshoe shaped collar that fits onto the three point lift. I was running the cylinder in and out, didn't notice the linkage bind, popped off the end. I'm hoping I can just weld it to the horseshoe, if not, I will have to buy a new cylinder, about $400 I don't want to spend....

we used to build the rods where I worked its a special meterial ( well its not cold-roll) but it may be cheaper than a cylinder . do you live close to a machine shop ? they are not complicated to take apart.