mrtosh

Just finished up my cam and valve spring install. Everything was going smoothly, had her all buttoned up and when it fired up the AC belt jumped and the idler pulley in the main belt system was squeeling like crazy. Turns out the Crank pulley was not pulled on all the way back. I tore apart the front again and tried to pull the crank bolt out, because it was not tightening any more. After using a breaker bar w/a 4' cheater bar, the bolt snapped. It snapped off right where the threads start in the crank. We tried drilling it and getting an easy-out in there, but the f*cker is not moving and really don't want to break the bit in there either. I'm guessing the bolt got cross-threaded in there somehow. What would my next option be? A couple of guys have said they've heard of guys doing this and threading the end of the snout and putting a slightly bigger bolt in there while keeping the broken piece in there. I've done prolly three cam changes in my life and have removed somewhere around 20 harmonic balancers and have never run into a problem like this. Any suggestions would be greatly appreciated.

TIA guys,

Sean

matt94z

iTrader: (49)

If you have any threads sticking out, you could try to put a nut on it and weld the inside. You might be able to turn it with a wrench. If not I would just keep drilling it one size up at a time. You could even try a reverse drill bit.

mrtosh

The threads are broken off about 1 1/2" in the snout of the crank, or else I def. would try that. Tried the reverse drill bit, but nothing happened.

ABQ99TA

iTrader: (17)

I FEEL YOUR PAIN BROTHER. I had almost the same thing happen last week when I was taking the bolt off. I had not fiished the install yet, I had only done the springs. I'm still trying to get the bolt out. I have drilled it almost as big as I can with out fuc--- up the threads. If I find something that works I'll let you know. I would love to hear how you get it out if you do as well.

mrtosh

Thanks for the support bro. There's a guy on the GTO forum who says he drilled the bolt, tapped it, and put a 1" stud in it w/a nut and lots of loctite. Has worked for him for over 20K miles. I'm thinking of doing this or since the bolt broke off about 1 1/2" in the snout just tapping the smooth part of the snout and putting in another bolt, while leaving the broken piece in there...

vettenuts

iTrader: (4)

I would tap the end of the snout. Measure ID and figure out what thread has that approximate minor diameter. Fine thread may be a better option since length is limited. You will then need to calculate a new torque value based on the thread diameter, pitch, etc. The only problem with this method is you won't have correct bolt stretch, so I would pin the damper for this reason. If you are running SLP, ATI or Powerbond, they already have a key milled in the hub and the ATI pin kit works really well.

matt94z

iTrader: (49)

You may try soaking it down with pb blaster, it really pulls into the threads and may be enough to free up the bolt while using an Easy out.

mrclean200518

iTrader: (89)

this may sound crazy but i hear taking a bottle of caned air and turning it upside down and trying to freeze the metal makes it shrink and it will come out easier

mrtosh

I'm thinking of doing this or what a guy did on the GTO forum. He ended up drilling it and putting a 1" diameter stud in there w/a lock nut. Can you pin a stock damper? Where would I get this kit?

Thanks again

vettenuts

iTrader: (4)

You can pin the stock damper, but the damper must be machined or you can end pin it but that puts two grooves in the crank snout and I am not a big fan of this method.

vettenuts

iTrader: (4)

Here, check this thread:

Link

eallanboggs

iTrader: (1)

Now that the damage is done you might think about some future precautions. You might want to grind a flat on one side of the old pulley bolt(you're going to throw it away anyway) and use it to chase the threads just to be sure there aren't any burrs before you install the new bolt. As the crank pulley is being pushed on you can see the pulley moving. I like to observe the relative position of the pulley to the timing cover seal as the pulley is being pushed home. When the snout of the pulley bucks up against the boss on the crankshaft the pulley stops moving and the torque value needed to turn the bolt or tool sky rockets. The pulleys should be in alignment at this point so your belt isn't going to come off. The relationship of the pulley faces to each other can be verified with a straight edge to be sure they are aligned. Before you install the pulley you might want to run the new bolt in by hand. Using your fingers to run the bolt in no snags or burrs should be felt. If the bolt hesitates as you turn it in further clean up of the threads is needed. These few precautions take only a few minutes compared to the problems a broken crank pulley bolt creates.