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KX -- Is the break below the surface of the casting, or is some of the bolt shank sticking up? What is the attitude of the job . . . is the broken bolt on the top, side, or bottom of the casting? What is the working access like? How big of a hurry are you in? If the broken shank sticks out of the casting, wire brush the intersection of the shank and the casting to clean off the dirt and rust. Then douse the joint with a good penetrating oil. (Ford Motor spray-can penetrating oil, Kroil, and PBlaster are some of the better ones on the market) while tapping the end of the shank with a little-bitty hammer. If the bolt is broken off below the surface of the casting, use the biggest pin punch that will reach the broken piece to tap the broken end. If the broken bolt sticks out of the top (or side) of the casting, you can build a little dam out of toilet-bowl-joint wax ring around (or underneath) of the shank and fill the dam with penetrating oil to let it soak for a while. No need for the dam if the break is below the surface on the top side. If it's safe to do so, you can use a torch to heat the broken bolt and/or casting. Spritz on more penetrating oil while it's cooling. (Some people advocate using candle wax instead of the penetrating oil, applied when the joint is nearly red hot.) If enough of the broken bolt protrudes, use a pair of Vise-Grip pliers to apply a bit of alternating tightening-the-loosening force to the bolt while applying more penetrating oil. If you can use your third hand and the little hammer to tap on the end of the bolt while you do this, so much the better. Once the bolt starts moving, it'll come free with a bit more penetrating oil and wiggling. Not enough sticking up to grab? Hacksaw, grind, or file the broken bolt until the end is flush with the casting surface. If the bolt is broken off flush with or below the casting, evaluate your working clearances and decide if you'd rather drill the broken end for a broken-screw extractor or if you'd rather just drill out the broken piece. In either case, rig a drill guide IF AT ALL POSSIBLE. If you decide to try a broken-screw extractor, the Ridgid 2-piece straight-splined extractors are the best I've ever used. If you insist on using a "conventional" extractor, the tapered-square models work better than the twisted models within my experience. A box end wrench is fine for turning one of the Ridgid extractors, but don't even think of using anything other than a T-handle wrench on a conventional extractor. If you go the extractor route, drill all the way through the broken bolt (being careful not to drill through the casting) using the size drill appropriate to the extractor. Once you've got that nice hole down the center of the broken piece, use that hole to apply penetrating oil to the inside of the joint. A left-hand twist drill is ideal for drilling the broken bolt, as it will sometimes grab the broken piece well enough to turn it out of its hole. If you can't rig a good drill guide, center punch the center of the broken end and do your best to drill a centered hole straight through the broken bolt. In general, I'd suggest drilling the offending bolt out rather than messing with a screw extractor. With a good drill guide -- which can be as simple as a flat piece of half-inch stock with a drill-pressed hole of the appropriate size clamped to the casting -- you should be able to drill the broken bolt to the "tap drill" size of the casting thread. This will leave only a "worm" of metal in the internal thread that will usually unwind without too much trouble. If even the worm sticks in the hole, it will give way to a properly-sized tap. Let me encourage you to take your time and work carefully. That bolt took 53 years to get itself into the condition it's in . . . if you can afford the time a few days of soaking in penetrating oil will be a trivial part of the tractor's lifetime. Those same few days might also be trivial compared to the time and effort needed to recover from a gone-wrong "quick" fix. John
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