Yes, I have changed them, and it's a pretty simple operation. Like it was described in a previous post, break the damaged gear away with a big pry bar, and split the hub over the Woodruff key with a BFH and a sharp chisel. Turn the crank and cam so the timing marks align(Be sure to remember the teeth spiral together.) Heat the hub of the new gear with a Propane torch until it's too hot to touch, and quickly tap it onto the cam snout. Be sure to file or sand any burrs off the cam snout to prevent the gear from seizing up partway onto the cam. I used a big 3/4" drive socket the size of the gear hub to serve as a driver to prevent damaging the fiber part of the gear. If a CO2 fire extinguisher or a can of Freon is handy, freeze the cam hub just before driving the hot gear into place. I've also used an air chisel with a large flat bit to drive the gear on after heating it. It's not the best method, but when you're working for flat rate labor pay, taking the cam out of the engine is not an option!
Jerry
