Review on Liftmaster 41C4220A Chamberlain Craftsman LiftMaster by Jeremy Floyd

I just installed one of these in my Craftsman garage door opener. This is the same as all Chamberlain/Lift-Master openers. Having already done this with my other door opener, the whole project only took about 45 minutes, including assembly. Tool. As previously mentioned, the three screw holes in the round metal bracket for the entire sprocket assembly are unthreaded. Save yourself the hassle of threading the screws through before installation and then removing them. This makes them much easier to screw in when you actually install the sprocket. I don't remove the motor or anything else in the opener, just the outer cover. You can remove the three mounting bolts from the sprocket bracket using a 5/16" wrench for the 2 easy to access bolts and use a 1/4" ratchet and 5/16" socket for the harder to reach bolt. Do all this with the door closed and the carriage fully extended in the closed door position and latched to the door. I introduce the limits by removing the gear from the underside of the sprocket shaft (using a small plastic clip) and turning the mating gear on the limit switch assembly so, that the rightmost contact (seen from the back of the unit) was in the door down position. Then I reinstall the gearbox, making sure the switch contact is still in the door down position, and install the clip. This puts the door boundaries very close to where they should be. I only had to adjust the limit screw about 1/8 turns to fully close the door. I've just ordered another set to keep on the shelf for when the sprocket in one of my openers inevitably wears out again.