LiftMaster Belt Drive Belts & Rail Assembly Parts

Which LiftMaster Belt Do I Need?

Every LiftMaster belt drive opener uses one of two belts, and each belt comes in three lengths. The belt is cut to match your door height, not your rail length, and the two belt families are not interchangeable — the 41A5434 has 20 ribs in a 6" span and the 41A3589 has 12. Put the wrong one on and it will not seat on the drive sprocket.

The chart below does the cross reference for you. Find your opener model in the left column, then click the belt in the column for your door height. Every belt is also available in a lower cost aftermarket version, listed further down.

LiftMaster Belt Chart — Find Your Opener Model

Click the part number in the column matching your door height.

Factory Belt or Aftermarket Belt — Your Choice

We stock both versions of every belt. The factory belt is the genuine LiftMaster part in original packaging, the same belt the opener shipped with. The aftermarket belt is built to the same length, the same rib pitch and the same end fittings by an independent manufacturer, and it typically costs about a third of the factory price. It installs identically and runs the same.

For a homeowner making a one-time repair, the aftermarket belt is the sensible buy. Choose the factory belt if you need the genuine part number on an invoice, or if you are supporting a warranty claim.

Belt Specifications

Use this table to identify a belt you already have in hand. Measure it end to end and count the ribs.

Have a Chamberlain or Craftsman Opener?

Chamberlain openers use a different belt, the 41A5250 series, in the same three lengths. Factory and aftermarket both available: 41A5250 7 ft factory or aftermarket  ·  41A5250-1 8 ft factory or aftermarket  ·  41A5250-2 10 ft factory or aftermarket. Browse all Chamberlain opener parts.

Belt Drive Rail Parts Diagram

A belt rarely fails on its own. With the rail apart, check the idler pulley bracket at the door end, the trolley, and the belt tensioner — a seized pulley or a worn trolley will chew through a new belt in a matter of months, and all three are inexpensive next to a second belt. Use the diagram to identify your part, then click the part number in the table below.

First part of number below corresponds to diagram number above:

Rail Parts Not Shown on the Diagram