Carli AS-FPAP-17-LVL-DRIVER Progressive Add-a-Pack Leaf Spring for 17-26 F250

Vehicle Fitment

• 2017-2019 Ford F-250 Super Duty (4WD)
• 2020-2022 Ford F-250 Super Duty (4WD)
• 2023-2026 Ford F-250 Super Duty (4WD)
• 2017-2026 Ford F-350 Super Duty (4WD - see Fitment Notes for important F-350 advisory)

Fitment Notes

• 4WD models only - does not fit 2WD trucks
• This is the driver's side individual spring only - order with AS-FPAP-17-LVL-PASS (passenger side) for a complete rear set, or purchase the CS-FPAP-LVL-17 kit which includes both sides plus U-bolts, bump stop drops, and hardware
• Not recommended for F-350 applications - the F-350's stiffer factory main spring pack does not compress much unless under load, and installing the Add-a-Pack may actually make the rear suspension stiffer than stock; Carli recommends Full Replacement Leaf Spring Packs for F-350 trucks
• Replaces the factory lower overload spring - does not replace the entire leaf spring pack
• Designed to pair with Carli leveling front lift systems providing 2.5"-3.5" of front lift
• Provides 1/2"-1" rear lift over stock, creating a slight rear-high stance to match Carli leveling front lifts
• Eliminates the factory lift block
• Carli Commuter shock package "-B" tuning (AS-FLVLSPKG-CS20IFP-B) is specifically valved for stock springs with Add-a-Packs - do not pair with "-A" (Full Spring Pack) tuning

Features

• 6-leaf progressive design built by Deaver Spring Mfg specifically to Carli Suspension proprietary specifications
• Replaces the factory 1" thick lower overload spring that causes harsh, unpredictable rebound over medium to large bumps
• Progressive rate engagement provides smooth, predictable spring compression and decompression instead of the abrupt "wall" effect of the factory overload
• Maintains full OEM load capacity - the factory main springs still determine overall payload rating
• Dramatically improved rear ride quality when paired with a Carli suspension system
• Improved rear traction through more predictable spring rate progression
• Block-eliminating design removes factory lift blocks for cleaner geometry
• No-drill installation - bolts into factory leaf spring mounting points
• Built in the USA by Deaver Spring Mfg

Specifications

• Part Number: AS-FPAP-17-LVL-DRIVER
• Brand: Carli Suspension
• Manufacturer: Deaver Spring Mfg (built to Carli specifications)
• Type: Progressive Add-a-Pack Rear Leaf Spring (Driver Side)
• Spring Design: 6-Leaf Progressive Rate
• Rear Lift Height: 1/2"-1" over stock
• Replaces: Factory lower overload spring (1" thick non-progressive leaf)
• Load Capacity: Maintains OEM rating
• Quantity: Sold Individually (Driver Side Only)
• Companion Part: AS-FPAP-17-LVL-PASS (Passenger Side)
• Complete Kit: CS-FPAP-LVL-17 (includes both sides + U-bolts, bump stop drops, hardware)
• Position: Rear, Driver Side
• UPC: 883584152200

Included Components

• 1x Carli AS-FPAP-17-LVL-DRIVER Progressive Add-a-Pack Rear Leaf Spring (driver side only - U-bolts, bump stop drops, and hardware sold separately or included in kit SKU CS-FPAP-LVL-17)

Product Description

The Carli AS-FPAP-17-LVL-DRIVER is the driver's side progressive Add-a-Pack rear leaf spring for the 2017-2026 Ford F-250 Super Duty 4WD. Built by Deaver Spring Mfg to Carli Suspension's proprietary specifications, this 6-leaf progressive design replaces the factory lower overload spring - the harsh, 1" thick leaf that does not follow the contour of the rest of the pack and creates an abrupt, unpredictable "wall" when the suspension compresses into it. By replacing this single blunt overload leaf with a multi-leaf progressive pack, the rear spring rate transitions smoothly as the suspension compresses, dramatically improving ride quality over medium to large bumps while maintaining the truck's full OEM load capacity.

The factory overload spring is a primary contributor to the notoriously harsh rear ride of the Super Duty platform. When the suspension compresses far enough to engage the overload, the sudden spike in spring rate creates a jarring impact that reverberates through the cab. The Carli Add-a-Pack eliminates this problem by progressively adding rate as the suspension compresses, engaging additional thinner leaves instead of hitting a rigid wall. The result is a substantially smoother rear end that still supports the same payload as stock, since the factory main springs - which determine overall load capacity - remain in place. This modification also improves rear traction by providing more predictable spring behavior during acceleration and off-road driving.

This is the driver's side spring sold individually. For a complete rear Add-a-Pack installation, pair this with the AS-FPAP-17-LVL-PASS (passenger side) or purchase the CS-FPAP-LVL-17 complete kit which includes both sides plus U-bolts, bump stop drops, and all necessary hardware. This spring provides approximately 1/2" to 1" of rear lift over stock, creating a slight rear-high stance when paired with Carli's 2.5"-3.5" leveling front lift systems. It is important to note that Carli does not recommend the Add-a-Pack for F-350 trucks - the F-350's stiffer main spring pack does not compress enough under normal conditions for the Add-a-Pack to improve ride quality, and may actually make the ride harsher. F-350 owners should consider Carli's Full Replacement Leaf Spring Packs instead.