Hellwig 3512 LP-35 3500 lb Helper Spring 2011-2019 Silverado/Sierra 2500/3500HD

Vehicle Fitment

• 2011-2019 Chevrolet Silverado 2500 HD - All Trims (WT, LT, LTZ, High Country), All Cab Styles (Standard Cab, Double Cab/Crew Cab, Cab & Chassis), SRW only, 2WD/4WD - 6.0L V8, 6.6L Duramax Diesel
• 2011-2019 Chevrolet Silverado 3500 HD - All Trims (WT, LT, LTZ, High Country), All Cab Styles (Standard Cab, Double Cab/Crew Cab, Cab & Chassis), SRW only, 2WD/4WD - 6.0L V8, 6.6L Duramax Diesel
• 2011-2019 GMC Sierra 2500 HD - All Trims (Base, SLE, SLT, Denali), All Cab Styles (Regular Cab, Double Cab/Crew Cab, Cab & Chassis), SRW only, 2WD/4WD - 6.0L V8, 6.6L Duramax Diesel
• 2011-2019 GMC Sierra 3500 HD - All Trims (Base, SLE, SLT, Denali), All Cab Styles (Regular Cab, Double Cab/Crew Cab, Cab & Chassis), SRW only, 2WD/4WD - 6.0L V8, 6.6L Duramax Diesel

Fitment Notes

• MOUNTING KIT REQUIRED - SOLD SEPARATELY: The Hellwig 3512 is the spring leaf assembly only. LP Mounting Hardware Kit #25312, engineered specifically for the 2011-2019 GM 2500 HD/3500 HD platform, must be purchased separately and is required for installation. The 3512 cannot be installed without it.
• SINGLE REAR WHEEL (SRW) APPLICATIONS ONLY - this kit does NOT fit dual rear wheel (DRW / dually) trucks. Confirmed directly by Hellwig's product page. For 2011-2019 Silverado/Sierra 3500 HD DRW applications, see Hellwig part #3518, which is confirmed for both SRW and DRW on that platform.
• FACTORY CONTACT OVERLOAD SPRINGS - CRITICAL NOTE: Factory contact overload springs must be removed before installing the 3512. This kit will not fit on trucks equipped with factory overload springs unless those springs are first removed and discarded. May also require U-bolt or center bolt replacement during installation on some configurations.
• Fitment covers the GMT K2XX platform used on 2011-2019 Silverado HD and Sierra HD trucks - covering both the first generation of this platform (2011-2014) and the refreshed second generation (2015-2019). All cab and bed configurations are compatible.
• For 2020 and newer Silverado/Sierra 2500 HD and 3500 HD trucks (GMT T1XX platform), verify with Hellwig directly at 1-800-HELLWIG (435-5944) for the correct LP-35 part number and mounting kit for those model years.
• The 3512 does not fit the 2007-2010 Silverado/Sierra 2500 HD or 3500 HD (GMT900 platform) - those trucks require a different LP spring kit and mounting hardware. Confirm your truck's platform before ordering.

Features

• Up to 3,500 lb. level load carrying capacity - 40% more supplemental load support than the LP-25 (part #2512), engineered for the heaviest fleet, commercial, fifth-wheel, gooseneck, and truck camper applications on the GMT K2XX Silverado and Sierra HD platform.
• Progressive rate / Fulltime Spring Rate design - provides consistent, immediate load support as the factory leaf pack compresses, engineered for continuous and sustained heavy-load use where on-demand support is needed every time the truck is loaded.
• 4-leaf multi-leaf stack construction spans both sides of the rear axle, delivering maximum bilateral support, superior resistance to body roll and trailer sway, and consistent side-to-side leveling control under extreme and sustained payloads.
• Fully adjustable load rate - independent left/right adjustment via the LP mounting hardware U-bolts allows fine-tuning of load distribution and correction of uneven side loads from upfitter bodies, camper placement, or asymmetric commercial cargo.
• Each spring leaf is hot-formed and heat-treated from ASTM 5160 alloy spring steel for maximum strength, fatigue resistance, and durability under continuous daily heavy-duty use.
• Powder coat finish over all steel spring components provides corrosion resistance in road salt, Duramax diesel exhaust residue, and wet-weather underbody environments.
• Eliminates rear-end sag, squat, and body roll under heavy loads - restoring proper ride height, headlight aim, front-axle traction, steering response, and brake performance on trucks regularly loaded near their GVWR.
• Reduces leaf spring wrap-up and axle hop under hard acceleration - particularly beneficial for 6.6L Duramax diesel applications pulling fifth-wheel trailers or operating heavy upfitted utility bodies.
• "Set it and forget it" design - zero ongoing maintenance after installation. No air bags, compressors, sensors, or electronics to fail, leak, or service in the field.
• Bolt-on installation using common hand tools - no drilling, cutting, or permanent modifications required to factory suspension components.
• Manufactured at Hellwig's ISO 9001 and ISO 14001 certified facility in Visalia, California - made in the USA since 1946, backed by Hellwig's Limited Lifetime Warranty against manufacturing defects.

Specifications

• Level Load Capacity: Up to 3,500 lbs.
• Spring Series: LP-35 (Load Pro 35)
• Spring Rate Design: Progressive Rate / Fulltime Spring Rate
• Construction: 4-leaf multi-leaf stack
• Spring Material: ASTM 5160 heat-treated alloy spring steel
• Drivetrain Compatibility: Single Rear Wheel (SRW) ONLY - does NOT fit DRW/dually
• Leaf Spring Type Compatibility: Multi-leaf rear spring packs only
• Mounting Kit: Required - sold separately (Mounting Hardware Kit #25312)
• Drilling Required: No (U-bolt or center bolt replacement may be required on some configurations)
• Country of Manufacture: USA (Visalia, CA - ISO 9001 / ISO 14001 certified)
• Warranty: Limited Lifetime
• Quantity: Sold as a kit (spring leaves only - mounting hardware sold separately)

Included Components

• 2x LP-35 4-leaf spring assemblies (1 per side), ASTM 5160 alloy steel, powder coated
• Installation instructions
• Note: LP Mounting Hardware Kit #25312 is NOT included and must be purchased separately for installation.

Product Description

The Hellwig 3512 LP-35 Heavy Duty Load Leveling Helper Springs deliver the highest level of steel leaf spring supplemental load support in Hellwig's catalog for the 2011-2019 Chevrolet Silverado 2500 HD/3500 HD and GMC Sierra 2500 HD/3500 HD - 3,500 lbs. of progressive load capacity, 40% more than the LP-25 (part #2512). Designed specifically for the GMT K2XX heavy-duty GM platform, the 3512 is the go-to solution for fleet operators, commercial upfitters, fifth-wheel and gooseneck towers, and truck camper owners who push their Silverado or Sierra HD to or near its rated GVWR on a consistent basis. The Fulltime Spring Rate design provides immediate, consistent support as the factory leaf pack compresses, making it the preferred choice over the LP-25 for trucks that carry heavy loads day in and day out rather than intermittently.

The 3512 uses a 4-leaf multi-leaf stack construction spanning both sides of the rear axle for maximum bilateral load distribution and superior resistance to body roll and trailer sway. The required LP Mounting Hardware Kit #25312 (sold separately) provides the GM-specific U-bolts and axle brackets sized for the 2011-2019 Silverado/Sierra HD rear suspension, allowing installation without drilling and enabling independent left/right load adjustment. Factory contact overload springs must be removed before installation - this kit is not compatible with vehicles equipped with factory overloads unless they are first removed. The 3512 covers all cab styles (Standard Cab, Double Cab/Crew Cab, Cab & Chassis), all trims (WT through High Country/Denali), and both 6.0L gas and 6.6L Duramax diesel powertrains in 2WD and 4WD configurations.

This kit is for SRW (single rear wheel) applications only - DRW dually owners should see Hellwig part #3518, which is confirmed for both SRW and DRW on the 2011-2019 Silverado/Sierra 3500 HD. For the 2020 and newer Silverado/Sierra HD (GMT T1XX platform), contact Hellwig at 1-800-HELLWIG (435-5944) for the correct LP-35 part number. Manufactured at Hellwig's ISO 9001 and ISO 14001 certified factory in Visalia, California and backed by a Limited Lifetime Warranty.