Timbren FRTT350J Severe Service Rear Suspension Enhancement System is a heavy-duty suspension upgrade designed to improve load stability, reduce rear-end sagging, and provide additional support for Ford Super Duty trucks carrying demanding or top-heavy loads.
Featuring patented Aeon hollow rubber springs and an 8,000 lb rated spring capacity, this kit is engineered for demanding applications such as slide-in truck campers, salt spreaders, heavy equipment, and commercial hauling.
Unlike traditional air suspension systems, the Timbren FRTT350J requires no compressors, air lines, or manual pressure adjustments. Its progressive spring technology automatically responds to changing loads, providing additional stability and suspension support when needed.
Key Features and Benefits
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Severe Service Suspension Design: Engineered specifically for demanding hauling applications and top-heavy loads that require increased rear suspension stability.
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8,000 lb Rated Spring Capacity: Provides substantial supplemental suspension support without increasing the truck’s factory-approved payload or towing capacity.
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Patented Aeon Rubber Springs: Advanced hollow rubber spring technology provides progressive resistance as the vehicle’s suspension compresses.
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Reduces Rear-End Sagging: Helps minimize excessive suspension compression when carrying heavy cargo or transporting equipment.
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Improved Sway and Roll Control: Designed to reduce excessive side-to-side movement and body roll when hauling top-heavy loads.
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Automatic Load Adjustment: Progressive springs respond naturally to changing cargo weight and road conditions without requiring manual adjustments.
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Comfortable Unloaded Ride: Designed to maintain clearance between the springs and contact points when the truck is unloaded.
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Maintenance-Free Operation: No air compressors, air lines, fittings, or pressure monitoring required after installation.
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Easy Bolt-On Installation: Vehicle-specific mounting brackets allow installation using existing factory mounting locations without drilling.
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Durable Heavy-Duty Construction: Engineered for repeated compression and demanding commercial or recreational use.
Advanced Severe Service Suspension Technology
The Timbren FRTT350J features patented Aeon hollow rubber springs that provide progressive suspension resistance under increasing loads.
Unlike conventional suspension helpers that may apply constant resistance, Timbren’s rubber springs become progressively firmer as the suspension compresses.
This allows the system to automatically adjust to changing vehicle loads while helping reduce excessive suspension movement.
Its Severe Service configuration is particularly useful when carrying loads with a higher center of gravity, such as truck campers or mounted commercial equipment.
The system is designed to provide greater resistance to body roll and swaying when transporting these demanding loads.
Maximum Stability for Top-Heavy Loads
Transporting heavy or top-heavy cargo can significantly affect vehicle balance, suspension compression, and handling characteristics.
The Timbren FRTT350J is engineered to provide supplemental rear suspension support, helping maintain more controlled vehicle movement during demanding hauling applications.
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Helps reduce excessive rear suspension sagging.
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Improves resistance to body roll.
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Helps minimize side-to-side swaying.
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Provides additional stability when transporting truck campers.
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Supports more controlled handling under load.
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Cushions certain road impacts and suspension movement.
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Helps maintain a more level vehicle stance when carrying cargo.
The progressive rubber spring design provides additional support as the load increases, making it suitable for applications where stability is especially important.
Compatible Ford Super Duty Trucks
The Timbren FRTT350J is designed for rear suspension installation on selected Ford Super Duty trucks.
Compatible applications include specified configurations of:
Fitment varies by model year, drivetrain, suspension configuration, and factory equipment.
The kit is listed for various Ford Super Duty applications beginning with the 2015 model year, with compatibility extending to newer model years on selected vehicles.
Always verify the exact vehicle year, model, drivetrain, and suspension configuration against the manufacturer’s fitment information before purchase.
Rear Axle Timbren Vehicle Suspension TFRTT350J+1
Maintenance-Free Suspension Performance
One of the main advantages of the Timbren Suspension Enhancement System is its straightforward mechanical design.
Unlike air helper springs, the FRTT350J does not require air pressure to provide supplemental suspension resistance.
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No air compressor required
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No manual pressure adjustments
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No regular inflation or deflation
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No electrical connections required
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Automatic response to changing loads
Once correctly installed, the system provides progressive suspension support without the regular adjustments associated with air-based suspension accessories.
Comfortable Ride When Unloaded
The Timbren FRTT350J is designed to maintain a clearance between the rubber springs and the vehicle’s contact points when unloaded, where the specified installation permits.
This allows the factory suspension to operate normally during lighter driving conditions.
As additional weight compresses the rear suspension, the rubber springs progressively engage and provide extra resistance.
This design helps balance everyday drivability with the increased load support required for heavier hauling applications.
Easy DIY Installation
The Timbren FRTT350J uses vehicle-specific mounting brackets and existing factory mounting locations for straightforward installation.
No drilling or air line routing is required for the specified applications.
The kit includes:
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Two patented Aeon hollow rubber spring assemblies
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Two 1-inch rubber spacers
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Two steel mounting brackets
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Required installation hardware
The components work together to provide supplemental rear suspension support without replacing the factory suspension system.
Product Specifications
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Product Type: Rear Suspension Enhancement System
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Kit Classification: Severe Service
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Installation Position: Rear
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Vehicle Compatibility: Selected Ford F-250, F-350, and F-450 Super Duty Trucks
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Spring Technology: Patented Aeon Hollow Rubber Springs
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Rated Spring Capacity: 8,000 lbs
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Spring Material: Heavy-Duty Rubber Compound
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Installation Type: Bolt-On
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Air Compressor Required: No
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Maintenance: No Routine Air Pressure Maintenance
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Installation Hardware: Included
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Warranty: Timbren Limited Lifetime Warranty
Important Load Capacity Information
The Timbren FRTT350J has an 8,000 lb rated spring capacity. This rating represents the supplemental suspension system’s capacity and does not increase the truck’s manufacturer-approved payload or towing limits.
Installing this kit does not increase the vehicle’s Gross Vehicle Weight Rating (GVWR), Gross Axle Weight Rating (GAWR), or other factory-established load capacities.
All cargo, trailer tongue weight, and vehicle loads must remain within the manufacturer’s specified limits.
Ideal for Heavy-Duty Truck Applications
The Timbren FRTT350J is designed for demanding situations where additional rear suspension support and resistance to body roll are important.
Common applications include:
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Commercial service equipment
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Heavy construction materials
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Utility and work truck cargo
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Landscaping and maintenance equipment
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Other approved top-heavy loads
Its Severe Service configuration makes it particularly useful for trucks that regularly carry equipment with a high center of gravity.
Dependable Suspension Support Without Complications
Timbren FRTT350J Severe Service Rear Suspension Enhancement Kit combines patented Aeon hollow rubber springs, an 8,000 lb rated spring capacity, and durable maintenance-free construction in one practical suspension upgrade.
Designed for compatible Ford Super Duty trucks, the system helps reduce rear-end sagging, improve load stability, and minimize excessive sway and body roll during demanding hauling applications.
With its simple bolt-on installation, automatic load response, and long-lasting rubber spring construction, the FRTT350J offers a dependable solution for truck owners seeking additional rear suspension support without air compressors or regular maintenance.
