General: Sheared Bolt...Help!!

[Alf ista]

Disaster has come my way in the form of a sheared bolt. Any advice would be much appreciated. I was tackling my long awaited water pump renewal on my '70 B20 Amazon and I also wanted to put in a new thermostat. Everything was going fine, I had the rad out and the hoses taken off and then started removing the thermostat housing. Both bolts were stiff, but the left one came off eventually, but the right one refused to budge and eventually sheared right off. I was a bit miffed as ye can imagine. Now, I have some bolt removal kits and, full of confidence, I tried them out. The smaller bits didnt work, just kept turning. I had a bigger one that I left till last because I didnt want to risk damaging the sides of the housing. I used it attached to the drill and sure enough, it bit into the sheared bolt. But, still the bolt wouldnt move and eventually the drill actually started to burn out! And it wasn't a cordless, I mean a good 750 watt DeWalt! It really is stuck and now I am starting to get a bit worried. The housing eventually came off which left a bit sticking up. I tried cutting a groove with a hacksaw so I could get a slot screwdriver in it, but as expected that didnt work either. I have put plenty of WD40 on it but nothing is working. Advice please, I am afraid to go further in case I damage the block threads. Picture below, not a pretty sight........ Thanks in advance, Hugh.

[craig8661]

only thing i could think on is to drill it and tap it to the next size thred but see what others say first

[48pop]

File it flat, center punch and start drilling it out....Start with small drill and work up in steps then retap......I have never had any success with "easy outs" they break and make the job 10 times worse...

[Markomega25]

Three things I would try.

1. Get an aerosol can of 'Plus Gas', or 'heat freeze' and use them. WD40 is not a lubricant, it is a water dispersing agent and whilst good for most things doesn't always cut it for this type of job.

Soak the threads in Plus Gas (which is a parrafin based penetrant) and leave for an hour or two. Or try 'Heat Freeze' it is a mixture of parrafin plus it feezes any rust/corrosion, and the thawing action breaks up any corrosion around the threads, hopefully freeing them up.

2. File the top of the protruding bolt flat (as said before) and use a centre punch to punch two indents on the face of the bolt 180 degrees apart near the outer edge. Then hit each indent in turn anti clockwise swithing to opposite indents each time, the shock will likely get it moving.

3. Heat! use a blowtorch to heat the surrounding area up gently all over and when hot use method 2 above.

I have never had any succes in using bolt removers (easy outs) they are usually made of too soft a metal and just spin round on the job.

[loon]

all posible methods
but if you have acess to a welder you could try welding stud to what is left and file the excess weld off so the housing its again

just thinkin outside the box

LN

[tdz840]

I would advise filing the bolt level with the head then accurately center pop the affected bolt. Start with a small size drill then progressively work larger sizes. You need to take it out to just under 'core' size which for a 5/16th is around 6mm (eh what!!). Once there you should be able to 'collapse' the thread with a scribe or similar sharp pointed instrument. One thing when drilling to depth be careful how deep you go as you do not want to compromise the head. Get an idea from the other bolt hole.
From experience this is the only reliable method. Others may be quicker if the bolt frees but if that easi out or other method shears you are in a pot
HTH
Russ

[hairyapple]

I just can't sit by while certain members, who shall be nameless, besmirch the venerable easy out without defending it's vital role in removing a broken stud. I have been using them in all sorts of situations over the past 48+- years and have always found them to work well WHEN USED PROPERLY. If the stud in question was so rusted that the bolt head sheared off, why would anyone think that an ease out would somehow magically remove that same stud without first attempting to dissolve that bond. A few tips-use as big an ease out as you can, start the drilling process with a small pilot hole then move up to that max size. The removal of the core of the bolt will allow the threads to flex a bit making removal easier, try some "liquid wrench" first if available-if the area to be dismantled is accessible and the condition questionable (say you're about to remover the exhaust down pipe from the header), apply the l/w a few times in the days preceding the work as it will make a difference, heating with any torch should be done with great care especially if the surrounding area is cast iron-remember the friction from the act of drilling will produce quite a bit of heat anyway. And last of all BE PATIENT & use common sense. If an ease out is beginning to torque that's a clue that the tool is close to failing. Last of all, locate a heli-coil distributor in your area-just in case.

[Alf ista]

Just to update how it all went for me. Not great if truth be told, although it did work out ok in the end. Here is what happened and it may be of use to someone who finds themselves in the same predicament. A friend I know told me about using a proper stud remover, not just any stud remover he said, but a proper professional one. He explained about one he has which has a yoke to enable you to drill down the centre of the sheared bolt. Then you insert a hardened splined rod down into the centre of the bolt. Then you put a special nut over the splined rod and then you can use a spanner on the nut. Excellent sounds like a great idea and way better than the cheaper stud removers I was trying to use. This is a really great stud remover and in most circumstances it will undoubtedly work. But however in mine, it was not to be. I did as it said on the tin only for the splined rod to shear off!! Now I didnt put too much pressure on it, honest! Anyway, as you can imagine, I was pretty pi**ed off! I had now inserted a hardened steel rod all the way down the centre of the sheared bolt! There was no way that this rod could be drilled out, bits were bouncing off it. What I did was to drill around it using small 1.5mm or 2mm bits. As you can imagine most of them broke. I took me over two weeks and a shed load of patience but eventually I got the splined rod and the rest of the sheared bolt out. I thought I would definitley have to tap it after all the damage I did to the threads but luckily there was enough of them left and a plenty at the bottom of the hole. I ran a tap down it to clean it out and I was delighted to find that a proper sized bolt would still fit. Now I certainly learned a valuable lesson. If I had just kept drilling instead of inserting the rod I would saved myself a lot of hassle. Ah well, you live and learn I guess.