Rancho RS55377 RS5000X Front Shock for 2011-2024 Silverado/Sierra 2500HD/3500HD

Vehicle Fitment

• 2011-2024 Chevrolet Silverado 2500 HD (4WD/RWD, All Trims, 6.0L V8 Gas, Front, 0" Lift)
• 2011-2024 Chevrolet Silverado 2500 HD (4WD/RWD, All Trims, 6.6L Duramax Diesel, Front, 0" Lift)
• 2011-2024 Chevrolet Silverado 3500 HD (4WD/RWD, All Trims, 6.0L V8 Gas, Front, 0" Lift)
• 2011-2024 Chevrolet Silverado 3500 HD (4WD/RWD, All Trims, 6.6L Duramax Diesel, Front, 0" Lift)
• 2011-2024 GMC Sierra 2500 HD (4WD/RWD, All Trims incl. Denali, 6.0L V8 Gas, Front, 0" Lift)
• 2011-2024 GMC Sierra 2500 HD (4WD/RWD, All Trims incl. Denali, 6.6L Duramax Diesel, Front, 0" Lift)
• 2011-2024 GMC Sierra 3500 HD (4WD/RWD, All Trims incl. Denali, 6.0L V8 Gas, Front, 0" Lift)
• 2011-2024 GMC Sierra 3500 HD (4WD/RWD, All Trims incl. Denali, 6.6L Duramax Diesel, Front, 0" Lift)

Fitment Notes

• Fits both 4WD (4x4) and RWD (2WD) configurations across all listed models
• Designed for factory ride height (0" front lift) - for lifted applications, select RS55378 (1-2" lift), RS55380 (3-4" lift), or RS55382 (5-6" lift)
• Confirmed fitment spans 2011-2024; 2025 model year compatibility should be verified prior to purchase
• Fits both the GMT900 platform (2011-2014) and GMT K2XX platform (2015-2019) and T1XX platform (2020-2024) generations of the HD trucks - verify your specific model year uses the standard coil-over front suspension

Features

• Rancho exclusive Cross Tuned Technology pairs a patented rebound valving system with an advanced compression phase for improved handling and ride control on- and off-road, tuned specifically for GM HD truck platforms
• Progressive Engagement Valving custom-tuned for the Silverado/Sierra 2500 HD and 3500 HD front suspension - absorbs initial impacts gradually at low speeds and progressively tightens response as road and terrain demands increase
• Compression Control Valve regulates fluid transfer to absorb impacts without disc flutter, maintaining consistent damping control during towing, hauling, or off-road driving
• Twin-tube, gas-pressurized design at 150 PSI minimizes air-to-oil foaming and prevents damping fade under the demanding, sustained use typical of heavy-duty work trucks
• 2-1/4" (57.2mm) diameter shock body holds increased fluid volume for cooler operating temperatures and consistent performance at varying speeds and terrain types
• All-weather fluid rated for internal temperatures from -40°F to 248°F, providing reliable performance in extreme cold or heat across all climates and seasons
• Low-friction, self-lubricating seal retains gas and oil charge for faster rebound response and smoother compression over the full service life of the shock
• 16mm nitro-carburized piston rod resists scuffing and corrosion for long-term durability under daily work, towing, and off-road conditions
• 35mm sintered iron, glass-filled Fluon banded piston delivers precise shock motion control and enhanced responsiveness to changing road conditions
• Double-welded loops at stress areas ensure structural integrity under the elevated loads and suspension forces common to heavy-duty truck applications

Specifications

• Part Number: RS55377
• Series: RS5000X
• Position: Front
• Lift Height: Factory (0")
• Drive Type: 4WD and RWD
• Extended Length: 17.97" (456.4mm)
• Compressed Length: 13.67" (347.2mm)
• Travel Length: 4.30" (109.2mm)
• Shock Body Diameter: 2.25" (57.2mm)
• Piston Diameter: 35mm (Sintered Iron, Glass-Filled Fluon Banded)
• Piston Rod: 16mm Nitro-Carburized Steel
• Gas Pressure: 150 PSI
• Top Mount: Barpin (Cross Pin - XP15)
• Bottom Mount: Clevis
• Boot Included: Yes
• Hardware Kit Included: Yes
• Warranty: Rancho Limited Lifetime Warranty

Included Components

• 1x Rancho RS5000X Front Shock Absorber (RS55377)
• 1x Protective Boot
• 1x Hardware Kit (washers, bushings, and nuts)

Product Description

The Rancho RS55377 RS5000X is a front shock absorber engineered for 2011-2024 Chevrolet Silverado 2500 HD and 3500 HD, and GMC Sierra 2500 HD and 3500 HD trucks, in both 4WD and RWD configurations at factory ride height. This stock-length unit is compatible with all engine options offered across this platform - the 6.0L V8 gas (L96) and the 6.6L Duramax diesel (LML and L5P generations) - and fits all cab and bed configurations without modification. Built on Rancho's patented Cross Tuned Technology, the RS55377 pairs an exclusive rebound valving system with an advanced compression phase that delivers significantly improved front-end damping control compared to worn OEM shocks, whether you're highway driving, towing a trailer, or running off-road trails.

The Progressive Engagement Valving is custom-tuned to the front suspension geometry of the GM HD platform - at low speeds and in the initial stages of travel, the valving engages gradually to cushion cab impacts from road irregularities. As inputs intensify, the valving tightens progressively to maintain stability under load. The twin-tube, 150 PSI gas-pressurized construction prevents damping fade during the sustained shock cycling that's common in HD work truck applications - long highway hauls, rough jobsite roads, and repetitive towing cycles. The 2.25" shock body holds more fluid than standard-bore units, keeping operating temperatures lower and damping more consistent across long service intervals.

The RS55377 is a direct-fit OEM-replacement front shock for stock-height 2011-2024 Silverado 2500 HD, Silverado 3500 HD, Sierra 2500 HD, and Sierra 3500 HD trucks - spanning the GMT900 (2011-2014), K2XX (2015-2019), and T1XX (2020-2024) platform generations. For lifted applications, the companion RS55378 (1-2" lift), RS55380 (3-4" lift), and RS55382 (5-6" lift) provide extended-length options. Installation uses factory mounting hardware with the included hardware kit; no fabrication is required. Sold individually - two are needed for a full front axle replacement. Backed by Rancho's Limited Lifetime Warranty, the RS55377 is a proven, well-matched front suspension upgrade for GM HD truck owners looking to restore or improve ride quality and control at factory ride height.