Monroe 34812 Shock Absorber - Rear

Monroe Gas-Magnum Rear Shock for Heavy-Duty Trucks

Monroe Gas-Magnum Shock Absorber 34812 is built for midsize and full-size trucks and vans that need firm rear suspension control without a harsh ride. It is a fitment-based replacement for select Chevrolet Silverado 3500 HD and GMC Sierra 3500 HD rear applications, with a design that uses greater fluid capacity than standard 1-inch bore shocks for more efficient operation.

Key Features

• Rear suspension shock absorber for heavy-duty truck applications
• Firm damping control with a ride quality tuned to avoid excessive harshness
• Up to twice the fluid capacity of standard 1-inch bore shocks
• Loop bushing and sleeve upper and lower mounts
• Extended bumper stop included in the design
• Part number 34812 for direct catalog lookup

Product Details

The Monroe Gas-Magnum line is aimed at trucks and vans that carry load, tow, or see frequent rear suspension movement. This shock absorber uses a larger-capacity internal design to manage heat and fluid movement more efficiently, which helps maintain consistent damping under demanding use. Monroe 34812 is a rear shock absorber for 2020-2025 GMC Sierra 3500 HD and 2020-2024 Chevrolet Silverado 3500 HD, plus earlier Silverado 3500 HD and Sierra 3500 HD applications listed below. This part cross-references Monroe Shocks & Struts (e.g., 560653, 20906293) for the same application.

What It Helps Address

• Excessive rear bounce after bumps or dips
• Reduced control from worn rear shock absorbers
• Unstable ride quality in heavy-duty truck use
• Rear suspension movement that feels loose or underdamped
• Heat-related fade in demanding towing or hauling conditions

Installation Notes and Fitment

• Fits 2020-2025 GMC Sierra 3500 HD, rear
• Fits 2020-2024 Chevrolet Silverado 3500 HD, rear
• Fits 2011-2019 Chevrolet Silverado 3500 HD, rear
• Fits 2011-2019 GMC Sierra 3500 HD, rear
• Fits 2015-2018 Chevrolet Silverado 3500, rear
• Fits 2011-2013 Chevrolet Silverado 3500, rear

Upper and lower mounting type is loop bushing and sleeve mount with a 14 mm sleeve ID. Compressed length is 15.34 in., extended length is 22.35 in., and travel length is 7.01 in. Verify mount style and suspension dimensions against the vehicle before installation. Monroe 34812 is a rear shock absorber for Silverado 3500 HD and Sierra 3500 HD applications where the listed dimensions match the original setup.

Quality Assurance

Monroe Gas-Magnum shocks are engineered for truck and van duty, with a larger fluid capacity design that supports more efficient damping. This part is listed with a limited lifetime warranty on the applicable 2011-2019 Chevrolet Silverado 3500 HD, 2011-2019 GMC Sierra 3500 HD, 2015-2018 Chevrolet Silverado 3500, and 2011-2013 Chevrolet Silverado 3500 applications noted in the fitment data.