A bumping, knocking, banging, or clunking beneath the floorboard of a Ford Super Duty is likely caused by worn sway bar link bushings. The eyelets of the sway bar links use a rubber bushing to isolate vibrations and dampen harshness from the sway bar system's movement. When this material deteriorates, it leaves slack between the eyelet and connecting hardware. The resulting "play" in the sway bar links is the source of the sound; as the link move up and down and the slack is taken out it produces a knocking sound. The worse the condition of the rubber bushings, the worse the clunking sound. It is generally generated at all speeds and is worse on bumpy roads or terrain.
Sway Bar Basics
The sway bar is simply a torsional spring mounted longitudinally against the front axle. It is connected to the left and right frame rails by links that move up and down. Sway bars sometimes go by different names including stabilizer bar, roll bar, or anti-roll bar. The purpose of the sway bar is to reduce body roll while turning; during any turn, the outside tire has a propensity to lift as weight is transferred to the tire on the inside of the turn. The sway bar restricts this tendency and keeps weight more evenly distributed between the left and right tires. It can also help reduce body roll resulting from a swaying trailer, thus its function is quite important on heavy trucks like the Ford Super Duty.
Sway Bar Replacement Parts List
Inspection and any disassembly of the sway bar links should be performed with the vehicle parked on a level surface so there is no tension in the links. Note that the factory Motorcraft sway bar links are non-serviceable, grease free units. MOOG makes serviceable links with zerk fittings, so their replacements can be periodically pumped with grease. We cannot comment on the longevity of the aftermarket units with relation to the factory Ford ones, however they seem to be a good, economical USA made replacement option. The driver and passenger side sway bar links are not identical; the passenger side link has a larger offset in its shape and they are not interchangeable. Sway bar links should be replaced in pairs, not individually.
| Part Description | Part Numbers |
|---|---|
| Sway bar bushing (set) | Ford 2C3Z-5484-BA MOOG K80201 |
| Passenger side sway bar link | Motorcraft MEF206 MOOG K80273 |
| Driver side sway bar link | Motorcraft MEF205 MOOG K80274 |
How to Replace the Sway Bar Links on a Ford Super Duty
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- Park the vehicle on a level surface, set the parking brake, and chock the rear tires.
- Remove the driver and passenger side sway bar links. The bolt heads require a 15 mm socket/wrench while the nuts on the backside require an 18 mm socket/wrench.
- Remove the U flange securing the sway bar to the front axle using a 15 mm socket/wrench. Start by loosening each side, then remove each flange while supporting the sway bar.
- Note the difference in offset between the driver and passenger side sway bar links. The passenger side link has a much large offset; they are not interchangeable.
- Remove and discard the old bushings on either side of the sway bar. If they leave remnants attached to the sway bar, remove them with a wire brush, sandpaper, etc.
- Install the new bushings on the sway bar in the same orientation and position that the old ones were.
- Attach the sway bar to the front axle, installing the U flange and tightening lightly so that the sway bar can still rotate.
- Install the sway bar links and snug the bolts/nuts, then torque to 60 ft-lbs.
- Torque the sway bar U flange nuts to 35 ft-lbs.
- If the sway bar links are being replaced with serviceable units, install the zerk fittings and pump them with grease.
- Drive vehicle, preferably over rough terrain and low speeds (speeds bumps are a bonus) followed by several miles on a typical road.
- Re-torque all sway bar and sway bar link hardware.