Summary: The AERA (Automotive Re-builders Association) reported that the Kent Moore EN-47702 Bolt Extractor Kit can be used to help remove broken head bolts in the block or broken main bolts which sometimes break in GM 2002-2006 2.8, 3.5, 4.2 aluminum block engines upon removal. Due to the dislike metals seizing can occur, which may cause enough binding that results in breakage of these fasteners. Kent Moore makes OE essential tools for GM, Chevrolet, Buick dealerships; they produce a tool kit that was designed for extraction when these bolts break. The specialty tool number is EN-47702.

To try to prevent breakage to begin with the AERA recommends placing a socket on the bolts and tapping with a hammer. The vibration produced when this is done can sometimes be enough to alleviate binding. In my experience in similar situations; i.e. like when loosening exhaust stud bolts which are prone to breaking, an impact gun (with it’s hammer action) provides vibration as well that is helpful in loosening without snapping studs. Of course this is not 100%, but if you’re faced with a stuck bolt or stud and you can feel it stretching and not loosening, what do you have to lose? Quick bursts with the impact wrench forward and backward can sometimes do the trick. As far as the Kent Moore EN-47702, like many Kent Moore dealer tools, is over-priced. At around $400, the kit consists of a couple of guides, left hand drill bits, taps and easy outs. That’s a crazy price to pay for these tools in our opinion. In addition, even if using the tool kit is successful at removing the broken bolts, it’s likely that the threads will be damaged. That was the reason for the seized bolts to begin with right?

Broken Easy Out

Sometimes the easy out will be broken. How do you remove a broken easy out? We offer the Rescue Bit which is much more than a drill bit. The Rescue Bit is made of a Tungsten Carbide that is harder than easy out material. These are made in America. The inventor/owner refused to take production overseas. The quality of China’s material was just not the best… and when drilling out broken tooling the material has to be the best available. The Rescue Bit does not have any warranty due to it being a consumable type product. Just like other tools in the industry that don’t have a warranty. It’s also brittle due to the fact that it has to be harder than easy out and other similar tooling material. But the Rescue Bit offers a chance to remove broken tooling if used properly and patiently, letting the tool do the work. There’s a video on of the Rescue Bit in use. Watch it and you’ll be amazed with what is can do.

Repair Damaged Threads

OK so you got the broken bolt out. Now what about those threads that are booger-ed up in the aluminum? Just chasing damaged threads in the aluminum for critical fasteners is not such a good idea. Luckily we have Time Sert thread repair kits that can install a bushing type, threaded steel insert that is much stronger than the original threads. Steel is obviously much stronger than aluminum. GM authorizes Time Sert for thread repairs period. They recognize no other thread repair system. In fact GM engineers work with Time Sert to manufacturer thread repair systems that they use for warranty repairs.