Broke. Crankshaft bolt

WVboy92 · May 1, 2019

Hey y'all,

I'm the proud owner of a 1998 Mustang GT. I recently made the mistake of our purchasing a cheapo piggy back pulley set from summit racing. After fighting getting the after market onto the harmonic balancer, I slapped it on the car. Cranked it up and something didn't sound right. I took a look and noticed a slight wobble on the harmonic balancer. I thought maybe the aftermarket bolt hadn't properly seated the pulley so like a moron I cranked down on it. It snapped.

After tearing everything back down, I started drilling for an extractor. Get the extractor in, it snaps off. Using a Dremel and a tungsten carbide bit, I was able to grind it out. Redrilled the hole, stick a left handed bit in it. It snaps.

So my question is, once I get the remnants of the drill bit out, what's the best way to proceed in getting the bolt out. My father did something similar on a bronco II and wound up drilling the hole so big, he collapsed the bolt and jacked up the threads. As this is my only mode of transportation (lesson learned, if it's a project car, get an everyday driver) so I need some advice ASAP.

lwarrior1016 · May 1, 2019

Unfortunately, you’re doing it. If the extractor can’t get it out and you’ve got the hole centered really well on the broken bolt, you could potentially drill it bigger and bigger until the bolt is gone and then run a tap through the threads to clean them up. If you damage the threads though, (disclaimer: I dont know if you should actually do this or if it’ll even work) you could drill it larger and put a thread insert like a heli-coil or something.

WVboy92 · May 1, 2019

That's what I thought. I'm going to get the bit out tonight after work, then go for it.

WVboy92 · May 1, 2019

Thanks buddy!

evilcw311 · May 1, 2019

That would really scare the hell out of me to attempt. This isn’t exactly a “water pump bolt” or anything else. You get one attempt and that’s it. After that your looking at a new crank.

Good luck dude. Remember, patience is your friend here. We understand the need to get it going as it’s your dd but don’t let yourself get frustrated and rush it.

Small compacts rental cars are cheap as hell and come in handy at a time like this.

Sent from my iPhone using Tapatalk

OLD H2S · May 1, 2019

I have had that happen.
I heated up the end of the broken bolt with a torch HOT hot hot.
Then I MIG welded little spot welds around and around and built up a tit that a nut would sit on. Then heated up the tit and welded the center of the nut on to the tit and let get cold. Then spray the nut with Freeze It or a can of Dust Off turned up side down and get it COLD.
Smack it once with a hammer and turn out.
Or use an pneumatic hammer with a pin driver to the center of the nut.
Or the vibrations from a multitool held to the side of the bolt will work but it takes 2 minutes to loosen. You need vibration to break the grip of the over torqued threads.

When I got it out I got a piece of 12mm thread all in the right pitch from McMaster-Carr and made a stud to go in to the hole and use a big washer and 2 nuts threaded on the end to hold every thing tight to this day and it is much easier to remove and replace than a bolt that tears up the threads every time it is used.

A key thing to remember is Ford meant all these parts to go together 1 time. This is not the old days of good fasteners. This was built cheap as possible and crappy tapped threads are just fine if they go together once.

I have had a very bad time dealing with the crank bolts and even the ARP crank bolts have had problems. My 12mm stud is the way to a strong repair.

WVboy92 · May 1, 2019

I love what you did there. Unfortunately, I do not own a welder. Either way, I will work on getting the broken bit out tonight and see what I can do from there. Maybe a combo of heat and drill? Just spit balling here. Good news is my boss will let me borrow his truck, if we can get it running lol.

white95 · May 1, 2019

@lwarrior1016

This sounds so familiar...

WVboy92 · May 1, 2019

white95 said:
@lwarrior1016

This sounds so familiar...

Hey, is there past thread I can look at to glean some ideas?

white95 · May 1, 2019

WVboy92 said:
Hey, is there past thread I can look at to glean some ideas?

No, we broke a flywheel bolt off in my crank and had to pull it out. it went to a machine shop for repair.

You don't want that LOL

lwarrior1016 · May 1, 2019

Yeah, that was not a fun time. Luckily it broke before the engine went in the car. I do not want to re-live that mess.

Also, if you aren’t comfortable putting an insert in there, maybe you could drill it and tap it to 14mm then get a hardened bolt.

WVboy92 · May 1, 2019

white95 said:
No, we broke a flywheel bolt off in my crank and had to pull it out. it went to a machine shop for repair.

You don't want that LOL

Well, that makes my predicament not seem as bad.

white95 · May 2, 2019

Went from this:

To this:

...reeeally quick!

OLD H2S · May 2, 2019

Where you at in W. Va?

RAU03MACH · May 2, 2019

I would say take your time with a dermal , good luck with it

WVboy92 · May 2, 2019

OLD H2S said:
Where you at in W. Va?

Huntington

WVboy92 · May 6, 2019

Update-- in the midst of drilling and knocking at the bolt, it has come loose. Using a slotted screw driver, I am slowly working it out of the crankshaft. Wish there was a way to speed up the process, but it is what it is.

white95 · May 6, 2019

WVboy92 said:
Update-- in the midst of drilling and knocking at the bolt, it has come loose. Using a slotted screw driver, I am slowly working it out of the crankshaft. Wish there was a way to speed up the process, but it is what it is.

That is a promising development!