My last blog paid tribute to using an air hammer or hydraulic press to help disassemble machinery that resists disassembly. Here are a few additional details:
-Let's say you've got a bearing or gear stuck on a shaft, without enough room to get behind it and hammer it off the shaft. Put a pointed bit in the air hammer and wedge the tip of a pry bar behind the bearing or gear. Press the pointed end of the hammer bit into the end of the shaft and pry on the pry bar while you carefully "buzz" the shaft. Be very careful to keep the hammer bit centered on the shaft--let it walk toward the edge and you can mushroom the shaft and create additional removal problems.
-Have you got a big nut to remove, and don't have a socket or wrench that fits it? Grab the air hammer and that pointed bit and carefully hammer counterclockwise on the nut. The same trick will work on big hydraulic fittings--but for gosh sake be careful the pointed bit doesn't slip off and punch a hole in a hydraulic line.
-In my travels around farms, I've noticed there are two kinds of hydraulic presses in farm shops. Presses that obviously get lots of use, and presses pushed back in a corner and covered with dust. The "busy" presses uniformly have a shelf or rack nearby with lots of short pieces of pipe, thick chunks of flat iron and other scavenged accessories. That's because a press is pretty much useless unless the operator has the right bushing or block or anvil to match the bearing, shaft, gear or component he's trying to take apart. If your hydraulic press is sitting in a corner and hasn't been touched in years, think back, and how many times did you glance at it, approach it with a shaft or bearing in-hand, then shrug your shoulders and reach for the sledge hammer because you didn't have the right accessories to allow the press to do its job? The next time you clean your shop, instead of throwing away all those chunks of pipe and flat iron, spend a little time cutting them into short chunks so they'll be available the next time you want to use your press.