Remove a Woodruff Key

Woodruff keys are installed in the hub of pulleys and gears so that they do not slip on the shaft they are attached to. Most often, a thrust washer and threaded fastener hold the pulley in place, but even after these are removed, the pulley will refuse to move. When the pulley or gear refuses to move, these methods may help.

Steps

 * 1)  Use a penetrating oil to loosen any corrosion which may have the pulley seized to the shaft.
 * 2)  Remove the threaded fastener that holds the pulley in place.
 * 3)  Brush or lightly sand the shaft if there is rust or dirt built up on it.  The hub of the pulley usually a precision fit to the shaft, so even if you loosen it, this debris will prevent it from sliding off.
 * 4)  Place a prybar or large screwdriver behind the pulley to pry the pulley off, if there is a surface behind it to pry against.
 * 5)  Put the nut or bolt back on the end of the shaft far enough to engage the threads securely, leaving a space between it and the pulley.
 * 6)  Tap lightly on the fastener with a soft faced hammer or using a wood block to protect the fastener and shaft if you use a conventional hammer, while applying moderate pressure with the prybar or screwdriver.
 * 7)  Be careful you do not bend the pulley or damage the threads of the fastener.  Use only moderate pressure, and do not strike directly on the end of the shaft or the nut/bolt with a steel hammer.
 * 8)  Buy, borrow, or rent a "gear puller" if the previous steps did not work.  Many gears and pulleys have threaded holes machined into them to facilitate using these devices.  They are usually an assembly with a center bolt, a threaded hub, and arms to grip the gear or pulley.
 * 9)  Install the puller with the center bolt engaging the pulley shaft in proper alignment to prevent slippage, and hook the arms or install pulling bolts through holes provided.
 * 10)  Tighten the bolt of the gear puller until it is very snug, then tap the exposed end with a suitable hammer.  The combination of "drawing force" and shock of the hammer creating inertia on the shaft should free the pulley.
 * 11)  Slide the pulley free of the shaft.
 * 12)  Remove the Woodruff key with a pair of pliers.

Tips

 * For details on usuing the gear puller, refer to the web site;
 * http://www.ccohs.ca/oshanswers/safety_haz/hand_tools/gearpullers.html
 * PB Blaster, PB-40, and Liquid Wrench, trademarked products, are useful in freeing stuck mechanical parts.
 * Lawnmowers have a "shear" key, which prevents damage to the crankshaft, located in the hub of the flywheel or magneto. These often cause the engine to refuse to run, and are easily replaced when you learn how to remove them.

Warnings

 * Wear safety glasses when using a hammer to strike another metal surface or tool.
 * Use care using lubricating oils, they are often flammable and you should avoid contact with skin and eyes.

Things You'll Need

 * Wrenches.
 * Prying tool.
 * Gear puller, if needed.
 * Hammer, soft faced preferred.
 * Wood block.
 * Penetrating oil.

Related Tips and Steps

 * How to Get a Custom Made Tin Backsplash Installed
 * How to Fix Low Pressure in the Shower
 * How to Remove Mildew from Sheetrock
 * How to Repair a Zipper when the Slider Has Come Off Completely

Sources and Citations

 * http://www.ccohs.ca/oshanswers/safety_haz/hand_tools/gearpullers.html
 * http://www.repairfaq.org/sam/lmfaq.htm