Bilstein B6 4600 Rear Shock Absorber — 24-284721
Ford F-550 Super Duty 2017–2022 | Stock Height | Sold Individually

Replace worn factory rear shocks with a direct-fit Bilstein B6 4600 monotube damper built for heavy-duty work trucks. Part 24-284721 is application-tuned for 2017–2022 Ford F-550 Super Duty trucks at stock ride height, delivering tighter control when towing, hauling, or driving empty.

Short description
Bilstein 24-284721 B6 4600 rear monotube shock for 2017–2022 Ford F-550 Super Duty. 46mm gas-pressure design, yellow body, blue boot, limited lifetime warranty. Sold individually (2 required).

Product description
The Bilstein B6 4600 Series shock absorber is a factory-replacement upgrade for stock-height light trucks. On the F-550, that means more consistent damping than a typical twin-tube OE shock, less fade on long grades or washboard roads, and better rear-axle control when the bed is loaded or a trailer is hooked up.

A 46mm monotube body puts more oil volume and a larger piston in contact with the road. High-pressure nitrogen and a velocity-sensitive digressive piston react immediately to small ripples and large hits, so the truck stays planted instead of floating or bouncing. Valving is specific to this F-550 application—not a generic truck shock.

Installation is bolt-on. It uses the original springs and mounting points. No lift, no extra hardware, no reservoir. The yellow body and blue straight boot make it easy to identify as a genuine Bilstein 4600.

Best for daily Super Duty use, towing, chassis-cab work trucks, and anyone replacing tired rear OE shocks without changing ride height.

Key features

• Direct-fit rear upgrade for stock-height 2017–2022 Ford F-550 Super Duty
• 46mm monotube gas-pressure design for fade-free damping
• Application-specific digressive valving
• High-pressure nitrogen charge for consistent performance under load
• Smooth-body, non-coilover construction
• Yellow paint finish with blue straight dust boot
• Uses OEM springs and factory mounts
• Sold individually — two required per vehicle
• Limited lifetime warranty

Specifications

• Part number: 24-284721
• Series: B6 4600
• Position: Rear
• Ride height: Stock only — does not lift
• Internal design: Monotube
• Body / piston: 46 mm smooth body
• Reservoir: No
• Adjustable: No
• Finish: Yellow paint
• Boot: Blue straight (included)
• Upper mount: Eye 16 mm
• Lower mount: Eye 14.1 mm
• Collapsed length: 15.75 in (400.0 mm)
• Extended length: 25.15 in (638.7 mm)
• Stroke: 9.40 in
• Shaft diameter: 14 mm
• Quantity per vehicle: 2 (sold each)
• Warranty: Limited lifetime
• Origin: Mexico
• Typical OE refs: Ford BC3Z-18125-AP, HC3Z-18125-J
• UPC: 651860830438

Fitment

• 2017 Ford F-550 Super Duty 4WD
• 2018 Ford F-550 Super Duty 4WD
• 2019 Ford F-550 Super Duty 4WD
• 2020 Ford F-550 Super Duty 4WD
• 2021 Ford F-550 Super Duty 4WD
• 2022 Ford F-550 Super Duty 4WD
• Rear position (left or right — same part)
• Stock ride height only
• Confirm single vs. dual rear wheel and chassis-cab configuration
• Does not include extra mounting hardware beyond the shock and boot

Factory twin-tube shocks on a heavy F-550 heat up and fade when you tow or run loaded. The 4600’s monotube layout sheds heat faster and keeps damping consistent. You keep factory ride height and spring rates, so payload and towing ratings stay the same—you just get better control and a more composed rear end.