3L290 V-Belt – 3/8" x 29" Commercial Garage Door Operator Drive Belt

The 3L290 is a standard fractional-horsepower V-belt designed for compatible commercial garage door operators and other pulley-driven mechanical systems requiring a 3/8" wide belt with a 29" nominal outside length.

Its narrow 3L profile is commonly used in lighter-duty motor and pulley assemblies where compact sheaves and reliable power transmission are required.

Product Features

• Standard 3L-section V-belt

• 3/8" top width

• 29" nominal outside length

• Single-strand construction

• Designed for compatible garage door operators

• Suitable for fractional-horsepower drive systems

• Replacement for worn, cracked, stretched, or slipping belts

• Suitable for compatible pulley-driven mechanical equipment

Specifications

• Belt Number: 3L290

• Belt Section: 3L

• Top Width: 3/8"

• Nominal Outside Length: 29"

• Number of Strands: 1

• Belt Type: Fractional Horsepower V-Belt

• Application: Garage Door Operator & Mechanical Drive Systems

Common Applications

Suitable for compatible:

• Commercial garage door operators

• Older residential garage door openers

• Industrial overhead door operators

• Motor-to-pulley drive systems

• Light-duty mechanical equipment

• Compatible Allstar MVP operator applications

Belt Size Identification

The 3L290 designation identifies the basic belt size:

• 3L = approximately 3/8" top width

• 290 = approximately 29" nominal outside length

If the existing belt is clearly marked 3L290, this is typically the correct replacement size.

Compatibility & Matching

Before ordering, verify:

• Existing belt number

• Belt width

• Belt length

• Pulley groove size

• Operator model

• Required belt section

Do not select a replacement belt based only on approximate length.

A 3L belt is narrower than 4L and 5L belts and must be used with compatible pulley grooves.

Signs a V-Belt May Need Replacement

Inspect the existing belt for:

• Cracking

• Fraying

• Glazing

• Excessive stretching

• Missing material

• Belt slipping

• Squealing

• Excessive vibration

A worn belt can reduce operator performance and place additional stress on the motor, pulleys, shafts, and bearings.

Installation Notes

When replacing a V-belt:

• Disconnect operator power

• Properly secure the garage door

• Inspect both pulleys for wear

• Confirm pulley alignment

• Adjust belt tension according to the operator manufacturer's requirements

• Confirm proper belt tracking after installation

A loose belt may slip and generate excessive heat. Excessive tension can increase load on motor shafts, bearings, and pulleys.

Package Contents

• 1 – 3L290 V-Belt, 3/8" x 29"

Pulleys, motors, shafts, operators, and other drive components are sold separately.

Important Note

Always match the replacement belt to the original belt number and equipment requirements before installation.

Disconnect electrical power and properly secure the door before servicing any garage door operator or belt-drive assembly.