FR350SDF Heavy-Duty Rear Suspension Helper Spring Kit | 8600 lbs Capacity | Progressive Spring Rate | For Ford F-350 (2005-2016) 2WD/4WD

The FR350SDF Rear Helper Spring Kit is a robust, maintenance-free suspension upgrade designed for Ford F-350 owners who demand reliable performance under heavy loads. By delivering intelligent, load-proportional support, it not only levels your truck but also transforms its handling, making towing and hauling safer and more comfortable. The precision-engineered components ensure a perfect fit and durable service life, offering peace of mind for every journey, laden or light.

• 【8600 LB HEAVY-DUTY CAPACITY】: Engineered to provide substantial supplemental support, this kit effectively combats rear-end sag when towing large trailers (like RVs) or hauling heavy payloads in your truck bed, helping maintain a level and safe ride height.
• 【PROGRESSIVE LOAD RESPONSE】: Features advanced hollow rubber springs that deliver a variable spring rate. The more weight applied, the firmer the support becomes, automatically adapting to your load for optimal stability and comfort whether loaded or unloaded.
• 【ENHANCES STABILITY & CONTROL】: Significantly reduces problematic trailer sway, body roll, and front-end dive during braking when under load. This translates to a more planted, confident, and controlled driving experience during towing and hauling.
• 【DIRECT BOLT-ON REPLACEMENT】: A straightforward DIY installation. Replaces the factory jounce bump stops using the included vehicle-specific brackets and hardware. No drilling, no complex air lines—basic hand tools are all you need.
• 【ZERO-MAINTENANCE DURABILITY】: Constructed from high-grade, compression-resistant rubber and powder-coated steel brackets for long-lasting performance. Once installed, it requires no adjustments, inflation, or ongoing maintenance—a true ‘set it and forget it’ solution.