So I was putting my underdrive pulley on today and broke the balancer bolt in the crankshaft. I was loosening the bolt to put the new one in and it snapped. I have about 8 threads stuck in the crank. I tried to use a bolt extractor set and the extractor broke inside the bolt haha. Before I go completely insane anyone have any suggestions?

 

machine shop

 

man,
how did u do that, using a impact or what?
ive removed and reinstalled all kinds of pulleys on ls1 motors,
still havent broken one bolt yet,
good luck

 

Let me guess, you pulled the pulley on using the stock bolt? You don't have many choices if you are breaking extractors off.

 

Yeah pretty stupid right!! I'm just gonna take the motor out and take it to the machine shop. It has been suggested that I take a large drill bit and drill it out?? I feel like an idiot but It will get fixed

All in all I really should have the bottom end at least freshened up with new bearings and rear seal. Maybe this isn't that bad lol.

 

I did the same thing I was able to drill out the bolt and ret-ap it was better than pulling the motor. If you want ot pull it and fresh'n it up go ahead. If not i will try to find the thread I posted when it happenend to me. It just took some time i didn't have to really re-tap it I just ran a tap through after I got the bolt out just to clean the threads.

 

Here is the post when I broke mine. Their is also another guy who did the same thing that posted in this thread. What I did is post #35 and what he did is post #42. It is worth a look before you pull the motor. Good luck.

https://ls1tech.com/forums/generation-iii-internal-engine/783859-crank-bolt-broke-removal-now-what.html

 

ABQ99TA, I love your sig im the gm guy at a local mustang performance shop...the supercharger or turbo thing will get their panties all in a wad tommorow.

 

I can't take credit for that I stole it from an local guy here. I thought the same thing when I saw it I had to use it.

 

There is any easy fix to this guys, I have done it before. Leave motor in the car. PM me and I will tell you how to fix it, for less than $50 bucks in the car.

Joe

 

If you broke a bolt extractor or EZ out and it is now stuck in the broken bolt, you're screwed. They're near impossible to drill out.

 

Can you post the info for everyone to read and learn from? if not PM me also I'd like to know incase i run across this problem ever.

 

I'm pretty sure he hilecoils the smooth part of the crank with a larger bolt.^^^^^^^

 

This is why I hate extractors (AKA EZ outs). I'm a toolmaker and avoid the things like the plague. Usually you have to burn them out on an EDM, which means you need to take the crank to a machine shop with this capability. The extractor is as hard or harder than a regular drill bit, so good luck there. You might be able to get it out with a carbide bit if you grind the surface your drilling smooth and to a point in the center. Or take center punch and break it out. If you manage to get it out, you will need to use a tap drill (the right size for those threads) to remove the broken bolt and then finish with a tap to clean out the threads.

 

If the easy out is in there couldn't you use an air hammer to crush it to bits?

 

Trade secret. PM me if you want to know how. Heres a hint.... SBC/BBC, how is the balancer bolt/thread set up on those cranks? It sure isn't 4 inches down in the crank. Think about it?

 

I am in the middle of this right now. Broke a damn ARP bolt in the crank.

I had a machine shope use a lathe to drill a 3/8 hole straight dead center through a gm bolt. Now using that as a sleeve to drill into the bolt material way back at the end of the threads.

 

The thread was probably messed up when the bolt was installed and seized up when you were removing it.

With the broken extractor, you're out of options 'cos like the guy said, it'll be hard to get it out and EDM is the best way to get it out without messing anything else. But, since the thread starts deep in the hole you have a bunch of counterbore before the threads for bolt stretch, you could use a thread insert (not helicoil, but a sleeve type insert) and use a shorter bolt with a lockwasher/etc. and keep the broken bolt/thread in the bottom of the hole. Hope this helps.

looks something like this -->

 

i will tell you this those stock bolts are not very easy to drill, i took a old on center drilled it and truned it down to put my home made puller against, so i dont think its gonna be very fun drilling it in the car. but where theres a will theres a way, good luck

 

lehmans terms....tap the end of the crank and run a shorter bolt....I guess that would work...just seems like gm done the long bolt/deep threads for a reason....