KYB 565039 Shock Absorber - Front or Rear

KYB MonoMax Rear Shock for GM Trucks

The KYB MonoMax 565039 is a heavy-duty monotube shock absorber built for rear suspension use on select Chevrolet and GMC trucks and vans. It is aimed at drivers who tow, haul, or run vehicles with a higher center of gravity and need more controlled damping than a standard replacement shock.

For Chevrolet G10, G20, and G30, as well as GMC G1500, G2500, and G3500 rear applications, this KYB MonoMax shock is a direct suspension upgrade focused on stability, control, and durability.

Key Features

• Up to 40% more damping performance than standard shock absorbers
• Monotube design for consistent response under load and repeated use
• Zinc-coated stainless steel piston ring for sealing in harsh conditions
• Off-road dust boot included to help protect the shaft and seals
• Engineered to work with vehicles equipped with electronic safety systems such as ESC and ABS
• Compressed length: 13.31 in; extended length: 20.39 in; stroke length: 7.09 in
• Upper and lower mount type: E2 (12.8 x 41.3)

Product Details

KYB MonoMax is the brand’s truck-focused shock line, built for heavier-duty suspension demands rather than everyday light-duty comfort tuning. The large-bore monotube construction helps maintain fade-free performance when the suspension is working hard, such as during towing, hauling, off-road driving, or repeated load changes. KYB 565039 is a practical choice for owners looking for a rear shock absorber upgrade on classic GM truck platforms, including Chevrolet G10 rear shock, Chevrolet G20 rear shock, and GMC G1500 rear shock applications.

This part cross-references Gabriel 77355 for the same application.

What It Helps Address

• Excessive rear-end bounce after bumps or load changes
• Reduced control when towing a trailer or carrying cargo
• Shock fade during repeated suspension movement
• Loose handling on trucks with a higher center of gravity
• Wear from dirt and debris reaching the shaft seals

Installation Notes and Fitment

Fits 1978-1995 Chevrolet G10, rear. Fits 1978-1995 Chevrolet G20, rear. Fits 1978-1995 Chevrolet G30, rear, except motorhome chassis, except heavy duty chassis, and without dual rear wheels. Fits 1979-1995 GMC G1500, rear. Fits 1979-1995 GMC G2500, rear. Fits 1979-1995 GMC G3500, rear, except motorhome chassis, except heavy duty chassis, and without dual rear wheels. Verify mount style and suspension configuration before installation. The listed E2 upper and lower mounts must match the vehicle’s existing shock attachment points.

For Chevrolet G10 rear shock replacement, Chevrolet G20 rear suspension service, or GMC G1500 rear shock upgrade, confirm compressed length, extended length, and stroke length against the original part before final installation.

Quality Assurance

KYB designs the MonoMax line for demanding truck use, with a monotube construction and corrosion-resistant piston ring intended to maintain sealing performance in severe operating conditions. The part number 565039 is built for consistent control on GM truck rear suspension applications.