FR350SDJ

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 ½″ 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.

Key Features

• Reduces sag, sway, and roll when towing and hauling

• Comfortable ride, loaded or unloaded

• DIY installation

• Zero post-installation maintenance

Specs

• Rated Capacity: 8600 lbs

• Kit height without 1/2” spacer = 6.8125"”

• Kit height with 1/2” spacer = 7.3125”

Note: Even though you’re increasing the spring rate by adding this upgrade, this does not increase the GVWR (Gross Vehicle Weight Rating). Please make sure that the load does not exceed the GVWR set by the manufacturer.

What's Included

2 x ½" Rubber spacers
2 x Mounting Brackets
2 x Patented Aeon® SES suspensions (hollow rubber springs)
All necessary hardware