The Carli XHD +2000 lbs Progressive Leaf Spring Kit is a heavy‑duty rear suspension upgrade built for 2019 and newer Dodge Ram 3500 4×4 diesel trucks with a 4.25″ axle tube that regularly carry ~2,000 lbs of constant load (such as pop‑up campers and heavy gear). It’s a 1″ rear lift leaf spring system engineered with a progressive spring rate that supports significant weight while delivering optimized performance for heavy load‑carrying applications, not unloaded daily use. 

Unlike standard progressive springs, the XHD (Extra Heavy Duty) pack is specifically designed with a higher spring rate to keep the truck at its intended ride height under constant heavy load, helping maintain proper suspension geometry and stability under load. For best results, pairing with remote reservoir shocks and custom tuning is recommended to match the stiffer spring characteristics and improve ride quality and control.

Key Benefits

• Supports constant heavy rear loads (~2,000 lbs) without excessive sag

• Provides a 1″ rear lift for a balanced truck stance

• Progressive design improves load‑carrying performance and rear suspension control

• Ideal for trucks with pop‑up campers or heavy gear setups

• Requires proper shock tuning for optimal ride quality and handling

Fitment

• 2019+ Ram 3500 4×4 Diesel with 4.25″ axle tube

• Not compatible with trucks equipped with factory air‑assist suspension