Kenworth Window Regulator R21-1021

The R21-1021 is the Left-Hand (Driver Side) electric power window regulator for modern Paccar trucks. 

Key Specifications

Part Number: R21-1021 (also listed as R21-1021L)

Position: Left-Hand (LH) / Driver Side

Operation: Electric (Power)

Right-Hand Equivalent: R21-1021R

Vehicle Fitment

This Kenworth Window Regulator R21-1021 is specifically engineered for the "Next Gen" aerodynamic doors found in:

Kenworth T680: Models from approximately 2013 to 2021.

Kenworth T880: Vocational models using the same door architecture.

Peterbilt 579: Often shares this regulator assembly in specific configurations.

Quality and Testing

TinzerMotor produces these window regulators and window motors with a focus on long-term high quality and mechanical reliability:

Heavy-Duty Construction: Uses thickened steel plate components and reinforced pivot points to prevent the "sagging" or jamming common in lower-quality aftermarket parts.

Extensive Testing: Each unit undergoes rigorous cycle testing, involving thousands of manual rotations under simulated glass weight to ensure the internal gears do not strip or slip over time.

Precision Fit: Designed to align perfectly with the original door mounting holes, ensuring a "bolt-on" installation without the need for drilling or modification.

Please contact: 

Ms Riva  

Wechat/WhatsApp +86 15355970956 

Email: riva@ruishuoautoparts.com