Cognito 6" Progressive Lift Leaf Spring Kit | 2019-2025 Silverado/Sierra 1500

The Obsidian Vision

A complete rear leaf spring replacement for the 2019–2025 Silverado and Sierra 1500 that delivers 5-3/4 to 6-1/2 inches of adjustable rear lift in three positions — and does it with a progressive multi-leaf spring pack that rides better than the factory spring across the full load range. The Cognito 6-Inch Progressive Lift Leaf Spring Kit uses a higher leaf count to enable thinner individual leaf material, creating a more flexible and progressive leaf stack with a smoother, more linear spring rate curve throughout the entire suspension cycle. Military-wrapped spring eyes, diamond-cut inner leaf ends, and anti-friction pads between the leaves complete a spring pack engineered for durability, reduced noise, and the ride quality that a progressive rate system delivers over a conventional two-stage design. Two complete spring packs, a 2-degree pinion shim, and a set of heavy-duty 10-1/2-inch U-bolts are included. Before ordering: 2025 model year trucks require the Leaf Spring Top Plate Conversion (110-91316, sold separately); trucks equipped with the OEM composite mono-leaf rear spring require sourcing OEM-related components before this kit can be installed.

Concierge Fitment Guarantee

Every order is manually reviewed by our technicians to ensure 100% compatibility with your build before we ship.

Engineering Breakdown

• Delivers 5-3/4 to 6-1/2 inches of adjustable rear lift in three positions via a complete progressive multi-leaf spring pack replacement — the three-position adjustability allows the owner to select the desired rear lift height within the operating range without replacing the spring pack, providing flexibility for stance tuning and tire fitment optimization at the installed lift height.
• Achieves a smoother, more linear spring rate curve throughout the entire suspension cycle by using a higher leaf count with thinner individual leaf material — the progressive rate design provides a softer initial rate for light loads that firms progressively as the pack deflects under heavier loads, eliminating the abrupt rate transition of a conventional two-stage spring and delivering the consistent, linear compression rate curve that is crucial for excellent ride quality across the full load range.
• Incorporates military-wrapped spring eyes for enhanced eye durability and resistance to fatigue cracking, diamond-cut inner leaf ends to eliminate the shear stress concentration points that cause leaf breakage at the inner leaf tips, and anti-friction pads between the leaves to reduce inter-leaf noise and provide a quieter, smoother ride under all load conditions.

The progressive multi-leaf spring pack design achieves its ride quality advantage through the relationship between leaf count, leaf thickness, and spring rate progression. A higher leaf count allows each individual leaf to be thinner, which reduces the stiffness contribution of each leaf and allows the pack to engage leaves sequentially as load increases — producing the smooth, progressive rate curve that a thick, low-leaf-count spring cannot achieve. Military wrapping at the spring eyes encases the eye in a continuous wrap of spring steel that distributes the eye load across a larger surface area, preventing the fatigue cracking that develops at unwrapped eyes under sustained cyclic loading. Diamond-cut inner leaf ends eliminate the stress concentration at the inner leaf tip that causes shear-initiated leaf breakage. Anti-friction pads between the leaves prevent the metal-to-metal contact that generates the squeaking and harshness associated with conventional leaf packs under load cycling. The 2-degree pinion shim corrects the rear differential pinion angle at the elevated ride height to maintain proper driveline u-joint operating angles. Heavy-duty 10-1/2-inch U-bolts are included.

Audit Table

Verified Fitment (OFAS Standard)

✅ CONFIRMED — Chevrolet Silverado 1500:
2019–2025 Chevrolet Silverado 1500 Base, Custom, Custom Trail Boss, WT, RST, LT, LT Trail Boss, LTZ, High Country 2WD/4WD
2022–2025 Chevrolet Silverado 1500 ZR2 4WD

✅ CONFIRMED — GMC Sierra 1500:
2019–2025 GMC Sierra 1500 Base, SLE, SLT, Elevation, AT4, Denali 2WD/4WD
2022–2025 GMC Sierra 1500 AT4X, Denali Ultimate 2WD/4WD
2022–2025 GMC Sierra 1500 Pro 2WD/4WD

❌ REQUIREMENTS & CRITICAL NOTICES:
⚠️ 2025 MODEL YEAR — LEAF SPRING TOP PLATE CONVERSION REQUIRED: 2025 Silverado 1500 and Sierra 1500 trucks use a rounded factory leaf spring top plate that is not compatible with the U-bolts included in this kit. The Cognito Leaf Spring Top Plate Conversion (110-91316, sold separately) must be added to your order for 2025 model year trucks before installation.
⚠️ COMPOSITE MONO-LEAF REAR SPRING TRUCKS: This kit is not directly compatible with trucks equipped with the OEM composite mono-leaf rear spring. Trucks with a composite mono-leaf rear spring require sourcing the OEM-related components (spring perches, U-bolt plates, and related hardware) before this progressive leaf pack can be installed. Contact the OFAS team to confirm the required components for your specific configuration before ordering.
Requires rear pinion angle verification post-installation — the included 2-degree pinion shim corrects the pinion angle at the elevated ride height; verify driveline u-joint operating angles are within GM's specification before towing at rated capacity.
Requires rear alignment verification post-installation to confirm axle centering and tracking geometry at the new ride height.
Re-torque U-bolts after the first 500 miles of use.

Installation & Technical Notes

Estimated Install Time: 1.5-Hour DIY Install (with a 2-post lift or floor jack and jack stands, basic hand tools, and torque wrench — alignment verification recommended after installation)
2025 Top Plate: Add the Cognito Leaf Spring Top Plate Conversion (110-91316) to your order before scheduling installation on a 2025 model year truck. Install the flat top plate conversion before installing the U-bolts.
Composite Mono-Leaf Check: Before ordering, verify your truck's rear spring configuration. Composite mono-leaf springs are identifiable by their single-leaf construction and non-steel (composite) material. If present, contact the OFAS team to confirm the required OEM-related components before ordering this kit.
Lift Height Selection: Select the desired lift height position (5-3/4", 6-1/8", or 6-1/2") before installation. Refer to Cognito's included instruction sheet for the spacer block configuration corresponding to each position.
Pinion Shim: Install the included 2-degree pinion shim at the rear axle pinion before installing the U-bolts. Verify the pinion angle is within GM's specification for the installed lift height after installation.
U-Bolt Torque: Torque all U-bolt nuts to the specification in Cognito's included instruction sheet with the suspension at ride height under load. Re-torque after the first 500 miles.
Shipping Notice: This kit ships as a complete dual leaf spring pack with U-bolts and hardware. Contact the OFAS team to confirm shipping method and delivery timeline for your location.

Wheel & Tire Fitment

The Cognito 6-Inch Progressive Lift Leaf Spring Kit provides 5-3/4 to 6-1/2 inches of adjustable rear lift on the 2019–2025 Silverado/Sierra 1500 platform. Rear lift at this increment is typically used in conjunction with a front lift or leveling kit to achieve a level or slightly raked stance. Contact the OFAS team to verify tire and wheel fitment for your specific front and rear lift combination and desired tire size.

Our team is standing by to verify your specific rear spring configuration (multi-leaf vs. composite mono-leaf), 2025 top plate requirement, and desired lift height position for your Silverado or Sierra 1500 build. Purchase with confidence; we review every build.