This gear kit on amazon.
													
																	Garage door chain sprocket replacement. 
									
																	This is a video on how to change the gear sprockets in a craftsman garage door opener. 
																	Over time the sprocket s teeth can wear and the chain may jump or skip when the opener raises the door. 
																	If the gear and sprocket assembly breaks the motor runs but the door won t move. 
																	This diy repair guide explains how to replace the gear and sprocket assembly on a chain drive garage door opener. 
															
													
									
																	Https amzn to 2uwvnkj i m working on a chain drive opener. 
																	Chain drive garage door openers have a sprocket that is attached at the top of the motor. 
																	Amazon s choice for craftsman garage door sprocket replacement for liftmaster 41c4220a gear and sprocket kit fits chamberlain sears craftsman 1 3 and 1 2 hp chain drive models 4 8 out of 5 stars 1 216. 
																	Located at the top of the motor unit the gear and sprocket assembly drives the chain that opens and closes the garage door. 
															
													
									
																	If you replace the sprocket assembly in your chain drive garage door opener yourself you may be able to save a lot of money. 
																	This was a craftsman model 139 53976srt.