Review on Liftmaster 41C4220A Chamberlain Craftsman LiftMaster by Chuck Chen

The day before the new set arrives, spend some time getting the entire engine assembly out of the garage for some bench work. Photograph each connection and assembly as you disassemble the engine block. Before removing the motor from the garage ceiling, hang the rail with wire or zip ties. (I replaced the flat gear rather than the entire assembly associated with it.) Be sure to use a 5/32 mandrel to remove the large gear from the shaft. Hold the shaft in place with a screw before attempting to remove the pins with a punch. There is an empty hole on the shaft that can be used for this purpose. I found that the cover does not come pre-threaded in the appropriate assembly, so make sure you use the assembly with the cover to pre-thread the panel before attempting the final attachment. Dismantling the old block, including removing it from the garage, took about two hours. I expect the build will take a lot less time; maybe an hour. The later assembly was successful and the device is now in the garage. Follow the instructions to adjust the up and down ranges of the door after reinstallation. Also keep an eye on the strength setting; This can prevent the plastic flat gear from wearing out as much as before. I would also buy a set of gears for about $7 and put them in the motor case. next time. The worm gear doesn't go bad since it's made of harder plastic than the flat gear. Finally, liberally apply grease to the gears as instructed in the instructions. My original unit had almost no lube on the gears. Good luck and take your time to get the job done right. The attached photos should help if you forget where everything is connected.