Best Way To Remove Broken Timing Cover Bolt

[carnerd3000]

Thank you all very much for your responses! Some of the things you guys said I kind of suspected after my errors anyway, like the ft/lbs. wrench being too much and needing sealant at the bottom of the timing cover, but it's always good to get more opinions if you don't know for sure. Right now I have left-handed drill bits on the way, and I'm going to give those a shot when they arrive.

@thinger2 Thanks for telling me about drill speed; I wasn't completely sure whether to go slower or full throttle. I actually did try going slower at one point, but for the most part I went full speed. I'll of course keep referring back to this thread, and post what my results are when I get that bolt out, and then the cover back on.

 

[thinger2]

Thank you all very much for your responses! Some of the things you guys said I kind of suspected after my errors anyway, like the ft/lbs. wrench being too much and needing sealant at the bottom of the timing cover, but it's always good to get more opinions if you don't know for sure. Right now I have left-handed drill bits on the way, and I'm going to give those a shot when they arrive.

@thinger2 Thanks for telling me about drill speed; I wasn't completely sure whether to go slower or full throttle. I actually did try going slower at one point, but for the most part I went full speed. I'll of course keep referring back to this thread, and post what my results are when I get that bolt out, and then the cover back on.

Dont feel too bad about a couple of broken bolts.
When I was in high school I bought a 18 foot plywood skiff and two 1950s vintage Kiekheafer Mercury outboards.
I decided that both mercs needed a rebuild so I started to strip them down.
My crappy ratchet wouldnt budge those bolts so I used a 1/2 inch breaker bar.
And broke a bolt, and another bolt and on and on.
I didnt break all of the bolts, but I broke most of them.
Then I got really smart and decided to put the parts in Moms dishwasher.
It cleaned them really well!
It also plugged the drain full of grease and paint and flooded the kitchen which warped the wood floors and leaked into the basement.
Wrecked the dishwasher and the flooring.
But I wasnt done yet.
I traded the boat to a buddy of mine for a case of Rainier beer and some nasty yellow dried up dirt weed.
So he came over with a trailer, we drank the beer and smoked that crap and then we loaded the boat on the trailer.
On his way out of the backyard he hooked the neighbors fence and ripped down about twenty feet of it.
And this is part of how we both ended up working for a piano moving company to pay for it all.
I am paranoid about breaking bolts.

 

[SS Performance]

Make sure the bolts aren't bottoming out. If they bottom out before the shoulder makes contact they are more prone to breaking.

If a bolt is broken down in the hole I take a set screw, to use as a guide, and drill out the center of the set screw. This protects the threads from damage. Then unscrew the set screw and us an easy out to remove the bolt.

Good luck
Craig

 

[carnerd3000]

Alright, so believe it or not I still haven't gotten this last bolt out yet (and part of that is having bad weather and not having a garage). I actually managed to take a decent picture of what it looks like at this point.

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I admit I am loosing my patience on this, and I feel it has gotten to the point of absurdity, lol. I also know that the edge of the screw hole does not look great, but as long as it can still have a bolt threaded in, I'm not too worried. I was trying to drill a hole in it, with both a regular and a reverse drill bit, but the problem is that I keep having a hard time keeping the drill centered. I did try using the awe, as well as a flat chisel to flatten out the bolt, which then I could use the awe to mark my drill hole on. I'm just getting a bit flustered on what to do at this point.

Another idea I had was using a tap that had a pointed end like this one:

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And I thought that it could clean the threads, but also kind of ream out the bolt at the same time. Would this be okay, or is it a bad idea? And I won't attempt anything different until I get a response from you guys or people I know personally that have worked on cars. I'll just keep trying to drill. I manage to scrape off a bunch of flakes from the bolt every few hours.

 

[Schurkey]

You can't put a tap IN until you get the broken bolt piece OUT.

Get a REAL centerpunch and a hammer. Smack the piece DEAD CENTER and fairly HARD. Make a good-size centering divot to hold the drill bit. Preferably a reverse-cutting bit, but not absolutely needed. Inspect the other holes--find out how deep they are, and don't drill deeper than that.

You drill the bolt using the tap drill for that size hole. When you're done--if you do a good job, centered, straight, and true--you'll peel the bolt threads out like they were a loose heli-coil.

Some folks start drilling with small bits and "work up" to the larger ones. I think it's a total waste of effort, and a good way to wreck drill bits. However, if you do choose to start small, you can try using an Easy-Out. Do not break the Easy-Out, or you'll be in real trouble.

 

[Erik the Awful]

Use a center punch to put a nice divot VERY square in the center of the broken bolt. Get a 1/8" drill bit and drill a pilot hole about 1/4" deep. Get a drillbit near the size of the bolt's root, not the size of the threads. Drill out the center of the bolt. Get the remnants come out with a pic. If your hole is a little smaller, or if your hole is slightly offset, you may need to collapse the remnants inward with a tiny center punch and a tiny hammer. Clean with a tap.

Worst case scenario if you dork it up, use a helicoil kit to tap the next size up threads and then helicoil it back down to size. It's a timing cover, not a main cap.

 

[SS Performance]

Use a set screw. Thread it into the hole. Use the allan head in the set screw as a guide. Drill thru the set screw into the broken bolt. Then you can use a extractor to remove the broken bolt.

Good luck
Craig

 

[Schurkey]

You must be registered for see images attach

Use a set screw. Thread it into the hole. Use the allan head in the set screw as a guide. Drill thru the set screw into the broken bolt. Then you can use a extractor to remove the broken bolt.

You see threads in that hole that would hold a set-screw?

I don't.

 

[carnerd3000]

Quick update, in case anybody was still wondering: I didn't get the bolt out, so I ended up just using RTV around the area where that one bolt was to seal it. And then I just snugged down the other 7 bolts. I forgot to take pictures, and the car is back together now anyway. Not happy about it, but the way I see it as long as it will hold I won't worry too much about it. If I have to do timing chains or something like that in the future, that's when I'll try it again. Definitely a learning situation here, and I think I'd rather mess up my car than someone else's, lol. Again, thanks again for your advice. I really appreciate it!