While working on your Mopar...
While working on your Mopar is generally fun, breaking a bolt can ruin your day. This month we'll show you some tricks we use to remove broken fasteners.
We love driving our Mopars, and enjoy maintaining, repairing, and upgrading them as well. As most of you know, there's a certain satisfaction that goes along with being able to perform mechanical work, making restoring cars a relaxing and fun hobby. One part of the hobby that isn't relaxing, however, is when you break off a fastener either trying to remove it or by over-tightening. You know the feeling, it's about to break loose and then snap . . . often accompanied by bloody knuckles and various words that can't be used in front of children. And while a broken fastener is bad enough, attempting to remove it improperly can only make matters worse, adding to your aggravation.
After the cursing and Band-Aids, the fact is that the broken fastener must still be removed, so most of us go for the Vise-Grips, which is a big mistake. Do you really think that if the fastener broke using the proper tool to remove it that Vise-Grips will do anything but mar the remaining stub? Not likely. In fact, we usually recommend staying away from the Vise-Grips and using other techniques like drilling with a reverse bit, or using a bolt extractor, commonly called an Easy-Out, to remove the fastener.
While attempting to replace the valve cover and exhaust manifold gaskets on the '69 Chrysler Newport that we picked up recently, we broke a couple of exhaust manifold studs, and found fasteners that were previously broken, explaining the leaks we were trying to fix. It takes a little patience to remove broken fasteners properly, but it's possible to do with tools you either already have or tools that are available at the local hardware store. Follow along and we'll show you the tools and techniques we used to successfully remove our broken fasteners.
What happens if your broken...
What happens if your broken fastener still won't come out? Don't worry, we'll show you how to....
....oversize the hole and...
....oversize the hole and repair the threads using the HeliCoil technique in a future issue.
The only way to remove a broken...
The only way to remove a broken off and stuck fastener is to drill a hole straight through the center, increasing the diameter of the hole until the pressure is relieved and the fastener will come out. To ensure you drill in the middle of the bolt, use a center punch to dimple the metal.
If the remaining bolt or stud...
If the remaining bolt or stud isn't flat on the end, you can use a cutoff wheel or carbide burr with a die-grinder to make the surface flat for the center punch. Carbide burrs come in various sizes and can also be used to make a concave area in the center of the fastener for the drill bit to follow.
With a flat surface and a...
With a flat surface and a dimple from the center punch, you can begin drilling the fastener. Remember, drill slowly so the bit doesn't overheat, and use cutting oil or the equivalent to save the bit. Start with a small drill bit as a pilot hole and keep the drill as straight as possible.
On small bolts like our valve...
On small bolts like our valve cover bolt, you can use a reverse, or left hand, drill bit. Drill slowly with a bit smaller than the nominal diameter of the threads, and once the pressure is relieved, the remaining bolt will just back out of the hole on the bit.
Larger fasteners like our...
Larger fasteners like our exhaust manifold studs can be drilled in steps up to the nominal (inside) thread diameter, in our case 5/16, so long as the hole is straight and centered. If your hole is crooked or not centered, stop drilling before reaching the threads and move to the next step.
Once the hole is drilled to...
Once the hole is drilled to size all the way through the center of the fastener, a bolt extractor can be used to remove the remaining shell. Bolt extractors come in various sizes and designs. We prefer the square type like the ones on the right in this photo. Do not apply too much force to the bolt extractor because if you break it in the hole it will be much more difficult to get out than the original fastener. Don't ask how we know ...
Luckily, our exhaust studs...
Luckily, our exhaust studs all came out using this method. After removing any damaged fastener with machine threads,....
....use the appropriate tap...
....use the appropriate tap to clean the threads of any remaining corrosion so the new fastener will thread in properly.
What happens if your broken...
What happens if your broken fastener still won't come out? Don't worry, we'll show you how to oversize the hole and repair the threads using the HeliCoil technique in a future issue.