After cable replacement, Craftsman garage door won't "close", moves a few inches down, then back to further than it started - Home Improvement Stack Exchange
How to replace a garage door opener drive chain and cable assembly | Repair guide
Replacing the Gear and Sprocket Assembly on a Chain-Drive Garage Door Opener - YouTube
American Garage Door Supply - Garage Door Hardware; Type: Chain Drive Gear & Sprocket Replacement Kit, Direct Replacement for the LiftMaster; For Use With: Commercial Doors; Material: Metal - 14099451 - MSC Industrial Supply
Genie Garage Door Opener Belt/ Chain Replacement Carriage Assembly – The Genie Company
CRAFTSMAN 10' Chain Extension Kit - Amazon.com
How to Replace Garage Door Opener in 15 Minutes! - YouTube
Garage Door Opener Repair: Is It Better to Repair or Replace?