The Ford F-350 Super Duty is a towing powerhouse, but heavy loads can still push it to squat. The Timbren SES FR350SDJ Rear Kit provides up to 8,600 lbs of support with Aeon® rubber springs that automatically stiffen as loads increase. Built for 2017-2023 F-350 Super Duty, this kit installs quickly, preserves ride comfort when unloaded, and gives fleets, RVers, and heavy haulers confidence under max capacity.

Key Features & Specs:
Rated capacity: 8,600 lbs Kit height: 6.8125 in (no spacer), 7.3125 in (with ½â€³ spacer) Aeon® rubber springs for progressive load handling Stops rear squat, sway, and roll under load Maintains factory ride comfort when unloaded Simple bolt-on install with all hardware included Unstable loads while towing and hauling don’t just make for an uncomfortable ride. Difficult handling, rear sag, and corner sway create dangerous driving conditions — for you, your passengers, and other vehicles. Whether you’re towing your RV across the country or hauling hay down the highway, our Timbren SES kits level your load, making for a safe, controlled ride so smooth, you might forget you’re towing altogether. How? Our Aeon® rubber springs deliver a progressive spring rate. As load increases, our rubber springs push back harder, eliminating squat, sway, and roll . After installation, the rubber spring will be in contact with the vehicle’s frame. This contact won’t affect ride quality — you’ll still enjoy a comfortable unloaded ride , too. What makes Timbren SES kits different from other suspension enhancement systems? Unlike air bags, our kits require no post-installation maintenance . And unlike other systems, you can install and haul in under 30 minutes , right from your driveway.