The $14 part that fixed my swamp cooler rattle in Los Ranchos

Last month my swamp cooler started this awful rattling noise every time the motor kicked on. I figured it was the bearings or maybe the whole motor, so I was bracing for a couple hundred bucks. Turns out it was just the blower pulley nut that had worked loose after 2 summers of running. I found the actual spec in the manual online, it said to torque it to 15 ft-lbs and use thread locker. Cost me $14 for a new nut and some Loctite from the True Value on 4th Street. Took 20 minutes with a socket wrench and the rattle is completely gone. Anyone else had a cheap fix like this save them from a big repair bill, or am I just lucky?