Bolt broke off inside crankshaft

[99 E-klips gs]

Was putting a new head on and was down to the last thing. The crank pulley. I tried to torque down to spec and the tip (3/4" of it) broke off inside of it. About 2 inches deep. I was going to try to drill it and tap a screwdriver into it to see if it will come out. But wanted to ask what you guys suggest first. I really do not want to take crankshaft out unless I absolutely have to

 

[pauleyman]

The crank pulley doesn't screw into the crankshaft. It screws into the crank sprocket which is slid onto the crankshaft. Worst case scenario pull it down like a timing belt job and put another sprocket on it.

 

[99 E-klips gs]

Well there's some relief. How does the sprocket come off? Do I need to drop the oilpan at all? Not around my car ATM to look at it

 

[2gnt]

The crank pulley doesn't screw into the crankshaft. It screws into the crank sprocket which is slid onto the crankshaft. Worst case scenario pull it down like a timing belt job and put another sprocket on it.

Huh? Op has a 420a.

The crank pulley is bolted to the crank, try drilling a hole into the bolt and get the biggest bolt extractor you can fit.
Or maybe someone that has managed to do the same thing can chime in.

By the way how did you manage to break that bolt?

Dang looks like others have done the same vv
http://www.dsmtuners.com/forums/420a-bolt-tech/193184-help-broken-pulley-bolt-stuck-crank.html

 

[99 E-klips gs]

It broke after putting the pulley on and trying to tighten it down with the bolt

 

[cl1ckclack]

just drill it out, and helicoil it

 

[99 E-klips gs]

Would a helicoil work? Might be kinda hard to tap that

 

[psycho]

Might be kinda hard to tap that

That's what she said. Lol

You're going to have to drill it out.

 

[pauleyman]

Well crap...I was looking at new posts and didn't realize it was in the 420a section. What I said is true for 4g63.

 

[99 E-klips gs]

I'm sitting here drilling the bolt with a titanium bit and was going to try to use an easyout on it. But the damn drill bit won't dig into it far enough for the extractor to catch anything. Hard ass bolt

 

[Lou98GSX]

Use a reversible drill bit and while you are drilling it it could work its way out

 

[dsmspickdad]

Damn, been there before in the removal stage. Drill it using the step up drill bit exercise. Make sure that use lubricate the drill bit, add to the life of the drill bit.

 

[dj-t]

Find some cobalt or titanium bits, used lubricant and be patient. Good firm pressure and slow speeds. I usually use a carbide burr to open it up after I drill a big enough hole. Then going as close as I can to the threads and then break/bend what is left out with a screwdriver or pick.

 

[kchaazz]

As has been said a good drill bit is key. Cobalt is what you need here and a reverse drill bit is what should be used, cause if youre lucky the bit will grab and just unscrew the broken bolt right out of the crank. Two to three size drill bits, used from smallest to largest to progressively enlarge the hole through the bolt, thereby weakening the bolt enough to release it from the threads in the crank. Personally, I would at all costs try and avoid having to helicoil that hole because the harmonic balancer has got to be dead nuts centered with the center line of the crank. Not all of us have the tools and skill required to accurately drill and tap that hole as required, and you can imagine the detrimental effects an even slightly off center hole can have on your main bearings due to an off center harmonic balancer.

 

[99 E-klips gs]

I tried using a cobalt bit and I've destroyed 2 of them. It eats it up after awhile. My titanium bit is lasting a lot longer then the cobalt ones. If all added up, I have probably spent 2 total hours of drilling this bolt. I'm using the titanium bit with a firm(not hard) pressure, Iv tried variables with speed, tried 500rpm, 1000rpm, 2000, and 3000. With 2000 seems to get the most metal shavings dug. I am using a steady flow of wd-40. And has been through $15 of it . I guess I can just continue to dig until I finally get through. Dunno what other option I have

 

[kchaazz]

Try cutting oil. WD- 40 just sort of boils off, but cutting oil will hold up better. Are you using a reverse bit as well?

 

[oldag98]

Is the crank bolt on a 420A threaded normally or reverse threads, CW or CCW? Also, what is the best way to stop the engine from turning when trying to remove this bolt? I tried putting it in gear and applying the E-brake, but the engine is turning over and dragging the whole car, even with the E-brake applied. So, what suggestions are out there for easy removal of this bolt? This is holding up cam gears, timing belt, and oil pump swap... I am probably too scared to try to use the starter to break the bolt free, so please don't suggest that...

 

[bullettdsm]

Is the crank bolt on a 420A threaded normally or reverse threads, CW or CCW? Also, what is the best way to stop the engine from turning when trying to remove this bolt? I tried putting it in gear and applying the E-brake, but the engine is turning over and dragging the whole car, even with the E-brake applied. So, what suggestions are out there for easy removal of this bolt? This is holding up cam gears, timing belt, and oil pump swap... I am probably too scared to try to use the starter to break the bolt free, so please don't suggest that...

its threaded normal; righty tighty, lefty loosey

Air is the easiest way, but I suspect that you don't have access. If you can't get her to lock down using the methods you described (sorry I haven't had your problem before. I've always been able to get them off), the next step would be to attack the flywheel/flexplate. You can access it through the starter hole, or from underneath the engine (by removing the inspection plate). You will see the gear teeth and/or bolts to work with to get her to lock up.

 

[oldag98]

Thanks for confirming that. I have air, but my 420A is mounted front to rear, not transverse, and there is little room btw front of engine and the radiator/electric fan. I don't think I can get a 1/2" impact in there, but maybe a 3/8" air ratchet. I will try again tomorrow and if worse comes to worse, I will pull the radiator and get at it with the 1/2" impact.

 

[0Boost]

Reverse drill bits work wonders in situations like this. you can get a set from harbor freight that will work for your problem. they are only 10 bucks a set and will work if you don't want to spend a lot of money.


for the other guy with the rwd 420a. there is another option that I don't like to do but it works to get the bolt loose. use a long breaker bar and bump the starter. I don't like doing it this way and have only done it twice in my lifetime. a guy I work with does it anytime he cant get an impact on it. I tend to just try and lock the crank by the flywheel to hold it still. just make sure the handle is firmly against the ground.

 

[rough]

Let us know how it turns out! Spent this whole weekend replacing my damn water pump, I was so worried about snapping that crank bolt, instead I pooched my timing some how