The LiftMaster 15-40B18QJH is an OEM drive sprocket engineered for select LiftMaster commercial door operators that use a roller chain transmission. Identified on the sprocket as 40B18T with a 1-1/4 in bore, this component transmits power from the operator shaft to the door’s chain system for smooth, reliable travel. It serves as a direct replacement part for worn or damaged sprockets and helps restore correct chain engagement and drive efficiency in commercial and industrial applications.
Technical characteristics align with an ANSI #40 chain profile featuring 18 teeth in a B-hub configuration and a 1-1/4 in shaft bore. Compatibility depends on your operator’s shaft diameter and chain standard; confirm the operator manual or existing part markings (e.g., 40B18T, 1-1/4 in bore) before ordering. Installation is mechanical only—no programming required. Follow best practices for alignment and chain tension, use proper lockout/tagout procedures, verify keyway and setscrew requirements per your equipment documentation, and reinstall any required guards. This OEM LiftMaster sprocket is suited for commercial door operator service where an ANSI #40, 18-tooth, 1-1/4 in bore drive sprocket is specified.