Settle body movement and help restore the designed ride control of your Super Duty with the KYB Suspension Shock Absorber (MPN 3440121), a nitrogen gas-charged rear shock. It's a KYB-recommended OEM replacement that drops in as a direct-fit replacement for the 2017-2020 Ford F-250 Super Duty and 2017-2022 Ford F-350 Super Duty — see the Buyer's Guide tab for engine-level applications.
- Excel-G (OEA) design: Built on KYB's OE assembly lines using the same OE-quality components and calibrated to restore the vehicle's original, designed performance rather than change it.
- Nitrogen gas-charged twin-tube: Includes every quality component found in KYB's global OEM products, the preferred choice of many professional technicians.
- Triple-lip fluid seal: Helps reduce the chance of oil and gas leaking out.
- Vehicle-specific damping valves: Hand-assembled in-house to manage tire contact, steering response, and body movement, helping keep electronic safety systems performing as designed.
KYB uses strong, thick strut bodies and brackets to minimize flex and help maintain correct alignment. Worn shocks often show up as excessive bounce, nose dive under braking, or reduced stability — if the original rear shock is worn, this replaces it.
Interchange: HC3Z18125AB · HC3Z18125EB · HC3Z18125EM · HC3Z18125EN · HC3Z18125R · HC3Z18125S · HC3Z18125T · HC3Z18125W · LC3Z18125J
This part cross-references / interchanges with the following part numbers:
Frequently Asked Questions
What vehicles does this shock fit?
It's a direct-fit rear shock for the 2017-2020 Ford F-250 Super Duty and 2017-2022 Ford F-350 Super Duty. Check the Buyer's Guide tab for engine-level applications.
Is this a front or rear shock?
This is a rear-position shock absorber for the listed Super Duty applications.
What type of shock is the KYB Excel-G?
It's a nitrogen gas-charged, twin-tube design classified OEA (Original Equipment for the Aftermarket), built on KYB's OE assembly lines to restore the vehicle's original designed performance.
What are signs my rear shocks need replacing?
Common signs include excessive bounce, nose dive under braking, or reduced stability. Diagnose the cause first; if a worn rear shock is the issue, this replaces it.
Should I replace shocks in pairs?
This listing is for one shock, but replacing both sides on an axle together as a matched set is recommended for balanced, even ride control.
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