Kenworth Window Regulator R21-1020 R21-1021R

The R21-1021R is a power (electric) window regulator for the right-hand (passenger) side of Paccar-manufactured trucks. It is a modern OEM component used across both Kenworth and Peterbilt heavy-duty platforms. 

Key Specifications

Part Number: R21-1021R (Right-Hand).

Left-Hand Equivalent: R21-1021.

Operation: Electric power (Power Window).

Weight: Approximately 10 lbs. 

Vehicle Fitment

This part is specifically associated with newer aerodynamic and vocational cabs, most notably:

Kenworth T680: Commonly found in models from roughly 2013 to 2019.

Other Models: Shared across various Paccar platforms including T880, W900, and Peterbilt equivalents that use the newer door architecture.

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