2.5" 2024-2025 GMC Sierra 2500HD AT4X Standard Lift Kit by Cognito

The GMC Sierra 2500HD AT4X models come equipped from the factory with a unique suspension configuration marketed as a 1.5" lift. However, real-world comparisons reveal that the front suspension actually sits 2.5"–3" higher than standard 2500HD models, functioning more like a leveling kit, while the rear receives a true 1.5" lift. This additional height alters geometry and reduces front suspension droop travel—leading to top-out issues and increased wear on steering components like the pitman and idler arms.

Cognito's standard lift kit corrects these factory limitations with a comprehensive solution engineered for improved ride quality, durability, and performance. This system includes a subframe drop, taller knuckles, and front differential drops to safely achieve an additional 2.5" of front lift while restoring front droop travel to a minimum of 3". The rear is lifted an additional ½” by upgrading from the OEM 1.5" block to a 2" block with longer U-bolts. A non-torsion drop bracket is also included to retain factory torsion bar location, and the factory Multimatic DSSV shocks are retained via a billet front clevis extension.

While this kit offers a solid upgrade path for maintaining factory components, customers looking for maximum suspension performance and durability should explore upgraded packages with extended-travel shocks and control arms. For addressing the accelerated wear of factory steering components, Cognito’s patented Pitman and Idler Arm Support Kit is highly recommended.

Features and Benefits:

• Designed specifically for AT4X models
• Corrects factory ride height discrepancy: actual 2.5"–3" front lift, 1.5" rear lift
• Replaces factory geometry limitations with subframe, taller knuckles, and diff drops
• Restores front suspension droop travel to a minimum of 3" to eliminate top-out issues
• Replaces OEM 1.5" rear lift block with 2" block and longer U-bolts for additional ½" lift
• Maintains factory Multimatic DSSV shocks with billet clevis mount extension for the front
• Includes non-torsion drop brackets to retain torsion bars within the frame
• Improves ride quality, CV angles, and front suspension travel without cutting or welding
• Patented Cognito Pitman and Idler Arm Support Kit recommended for long-term steering durability
• Ideal for maintaining factory components while addressing OEM suspension shortcomings

Tire Fitment:

• Stock tire or 35x12.50 tire on stock wheel – Tire may look small aesthetically – 12.5” wide tire might require a 1/4” wheel spacer
• 37x12.50 tire on stock wheel – Requires at least a 1/4” wheel spacer– Tie back kit required – Medium trimming needed
• 35x12.50 on 10” wide wheel with +18mm offset – Tie back kit required – Medium trimming needed
• 35x12.50 on 10” wide wheel with 0mm offset – Tie back kit required – Medium trimming needed
• 37x12.50 on 9” wide wheel with +18mm offset – Tie back kit required – Medium trimming needed
• 37x12.50 on 9” wide wheel with 0mm offset – Tie back kit required – Heavy trimming needed
• 37x12.50 on 10” wide wheel with 0mm offset – Tie back kit required – Excessive trimming needed – Occasional rubbing may occur