Upgrade your Ford F-350’s rear suspension with the RAS HD Suspension Kit—designed to improve towing, hauling, and daily driving performance. This bolt-on RoadActive Suspension system strengthens your rear leaf springs, reduces squat, sway, and bounce, and delivers a smoother, more controlled ride whether loaded or unloaded.
Unlike air bag systems, RAS is fully mechanical and maintenance-free—no compressors, air lines, leaks, or constant adjustments. Each kit includes heavy-duty helper springs for the rear leaf springs, providing progressive support under load while maintaining same-as or better-than stock unloaded ride quality. Installation is quick and easy—about one hour from the box to the road.
*If your truck does have a factory top overload, it must be removed in order to install RAS.
Key Features:
• Fits 1973–2010 Ford F-350 trucks
• Strengthens rear leaf springs for improved load handling
• 3-in-1 system: helper spring, sway control, and traction support
• Reduces rear squat, body roll, bounce, and axle wrap
• Progressive load support for towing and hauling
• Maintenance-free design—no air lines or adjustments required
• Fully assembled for quick, bolt-on installation (~45–60 minutes)
• Proven RoadActive Suspension performance since 1998
Before You Order
Verify part number 3611-HD exactly Match the listed product details to the part you are replacing before ordering. Compare dimensions, specifications and fitment information with your RV or component.
Frequently Asked Questions
What part number should I verify before ordering?
Verify 3611-HD on your existing part, documentation or equipment label before ordering.
How should I confirm this part fits?
Compare the listed part number, dimensions, specifications and fitment details with your existing component. Do not rely on appearance alone.







