LiftMaster 16-4L290 Cogged V-Belt – 1/2" x 29" Commercial Operator Belt

The LiftMaster 16-4L290 Cogged V-Belt is a replacement drive belt designed for compatible LiftMaster commercial garage door operators.

Measuring 1/2" wide with a 29" circumference, this cogged V-belt transfers power within the operator drive system and is commonly used on LiftMaster medium-duty trolley and jackshaft operators manufactured after 2005.

Specifications

• Brand: LiftMaster

• Part Number: 16-4L290

• Belt Type: Cogged V-Belt

• Belt Size: 4L290

• Width: 1/2"

• Circumference: 29"

• Application: Commercial garage door operator

• Operator Type: Medium-duty trolley and jackshaft systems

• Color: Black

• Quantity: 1 Belt

Compatible LiftMaster Operator Series

Common compatible applications include:

• LiftMaster MT Series

• LiftMaster BMT Series

• LiftMaster MJ Series

• LiftMaster MH Series

• LiftMaster HMJ Series

Compatibility generally applies to supported commercial operators manufactured after 2005.

Always verify the operator model and existing belt size before ordering.

Cogged V-Belt Design

The cogged profile allows the belt to flex efficiently around operator pulleys while maintaining reliable power transfer.

Replacing a worn, cracked, glazed, or slipping belt can help restore proper operator performance and reduce unnecessary strain on related drive components.

When to Replace the Belt

Inspect the existing belt if you notice:

• Visible cracking

• Frayed or damaged edges

• Missing or damaged cogs

• Belt slipping

• Excessive belt noise

• Operator motor running without consistent door movement

• Excessive looseness or stretching

These symptoms can also indicate pulley, bearing, tension, or door-balance problems, so the complete operator and door system should be inspected when premature belt wear occurs.

Important Compatibility Information

Commercial operator belts are identified by both their width and circumference.

Before ordering, confirm:

• Existing belt marking: 4L290

• Belt width: 1/2"

• Belt circumference: 29"

• LiftMaster operator model

• Operator production generation

Do not select a replacement belt based only on appearance.

Installation

Disconnect electrical power to the commercial door operator before servicing the drive system.

Proper belt tension is important. Excessive tension can damage bearings and other operator components, while insufficient tension can cause slipping and poor performance.

Commercial overhead door systems involve heavy doors, moving components, and high-tension hardware. Professional installation by a qualified commercial door technician is recommended.

If you are unsure whether the LiftMaster 16-4L290 belt fits your operator, contact Garage-DoorParts.com with your operator model number and the markings from your existing belt before ordering.