The LiftMaster 144B42 Drive Belt Pulley 28T is a genuine OEM replacement pulley for select LiftMaster and Chamberlain belt-drive garage door openers. Featuring a 28-tooth profile, it engages the drive belt to transfer motor power to the rail system, helping restore smooth and quiet door operation when the original pulley is worn, cracked, or noisy. This replacement part is intended for residential belt-drive units that specifically list 144B42 in their owner’s manual or parts diagram, and is commonly searched as a motor pulley, belt pulley, or 28-tooth pulley for LiftMaster/Chamberlain openers.
For installation, disconnect power to the opener, release belt tension per the manufacturer’s instructions, and replace the pulley using the opener’s original hardware and alignment procedure. After reassembly, re-tension the belt to specification and verify door travel limits and safety reversal functions. This component is not interchangeable with chain-drive sprockets or pulleys with a different tooth count; always confirm compatibility by matching part number 144B42 to your exact opener model and revision. Proper installation and alignment help maintain belt tracking, reduce slippage, and support reliable, long-term operation.