broken bolt removal UPDATE

On my WD, the rear bolt on each of the hangers for the drawbar support have been broken off flush with the bottom of the transmission, and I have put off dealing with them until I started pulling the last couple years. Just wanted to get some opinions on how to approach the removal of said bolts. There is absolutely no thread sticking out below the hole, and I am not sure if they are rusted in, but I'm sure they're hardened and a pain to drill laying under the tractor. This may be interesting.

UPDATE: got one bolt removed by drilling out center and using square bolt extractor, no rust on bolt, pretty good crack when it broke free though. But on the second bolt, I broke a small drill bit off in the bolt after drilling about 1.5" deep, have a nice bigger hole drilled up to broken bit now but bits just quit cutting even when sharpened. Tried welding a nut to the bolt before drilling but didn't work. Should I try a left-hand drill bit? I am just about at wits end here.


Edited by Bill_MN - 25 Jul 2011 at 10:50pm

is there any way you could weld a smaller bolt or nut  to the one that broke off and remove it that way ive heard that that way works good sometimes good luck

Weld a nut onto the end, not only do you have something to turn, the heat from the weld helps to free the stud.

I saw them putting a car frame on a jig that they could turn it like a motor stand on one of those restore shows.

Coke-in-MN wrote: weld a washer on first then weld the nut to that. easier than reaching down into nut for first weld. take a old candle or color crayon and melt wax into area also to loosen and lube broken part.

Agreed.  By the time you try to weld to the inside of a nut you'll barely have any contact.  The washer trick works great!

Here is how I would do it.  First drill out the center of the bolt with a third the size of drill bit. Then take a wire welder weld the center back in. Then weld on a washer. As the bolt starts cooling, take a candle to the bolt. As it cools to the right temp, the wax will wick around the threads just like when you solder a pipe joint. Then take a pair of pliers and turn it out. The welding of the bolt hole makes the entire bold red hot, that breaks all of the rust loose by the swelling and shrinking, then the wax allows you to easily remove.  Dave.

Thanks for the input guys, I never thought of welding a washer on first to extend it below the hole, that sounds like the bset way. Not sure if the candling would work going up as the bolts are beneath the tractor? Dave63, I agree a rotisserie would be great... but probably a little overkill!

Edited by Bill_MN - 16 Jul 2011 at 8:45am

I never seem to have any luck with the easy outs. Not much fun when the easy out breaks off in the bolt. Always come out using the welding/candle method or heating/candle only if its possible. Sometimes takes a few heat cycles.

Find the center of the broken bolt and center punch. It will most likely be slightly off center so take a 1/8" drill bit and walk the dint to a exact measured center. Drill the 1/8" hole on center straight and square. Enlarge the hole with a 1/4" drill bit. this will give you a pilot hole that will keep the tap drill for most sizes on center. Pick out the first thread or two with a sharp scribe. Sometimes the thread will coil out with pliers but not often. Start the tap but only turn in a 1/4 turn to chip out the old threads and back the tap up.  This will go much faster than you would ever imagine.  Probly faster than getting the welder around.

Start with the simple stuff first.

If you are going to use the punch and chisel method, be very careful you don't swedge the bolt into the threads in the tractor. If it will come out this way, bigger is not better. After making your initial notch, groove or punch mark, use a small hammer and center punch to walk the broken piece in a circle with light taps.

Edited by CTuckerNWIL - 17 Jul 2011 at 9:50am

on the subject of the welding, if a stud is ever broken off below the hole, there is a good stick weld rod i think it is called stud saver. you build up the stud by slowly weld, cool, weld, cool, small incriments, building up the stud until it is above the hole, then weld a big nut onto it and let it cool entirely. then tighten slightly then work back and forth until it comes out, the rod weld does not stick to the inside threads because the flux is made with silicone and actually will not adhere to the threads. you can get head bolts out several inches down inside a block. takes some time but works really well. never heard of the wax trick, i will have to try it.

bump

Bill_MN wrote: Thanks for the input guys, I never thought of welding a washer on first to extend it below the hole, that sounds like the bset way. Not sure if the candling would work going up as the bolts are beneath the tractor? Dave63, I agree a rotisserie would be great... but probably a little overkill!