Complete removal and replacement of the power steering gear box (rack and pinion assembly) on a 2021-2024 Ford F-150 with 3.5L EcoBoost engine.

Warnings

Tools required

Parts

• Power steering gear box assembly × 1 — Use OEM specification
• Steering gear O-ring kit × 1 — Use OEM specification
• Cotter pins for tie rod ends × 2 — Use OEM specification
• Intermediate shaft coupling bolt × 1 — Use OEM specification
• Power steering fluid × 1 — Motorcraft MERCON ATF

Fluids

• Motorcraft MERCON LV ATF — 1 qt

Preparation

1. Park vehicle on level surface with front wheels pointed straight ahead
2. Disconnect negative battery terminal and wait 2 minutes for airbag system to deplete
3. Lock steering wheel in centered position using steering wheel holder or seat belt through wheel
4. Raise and safely support front of vehicle on jack stands at frame rails
5. Remove both front wheels
6. Place drain pan under power steering gear box
7. Extract as much power steering fluid as possible from reservoir using turkey baster or pump
8. Mark relationship between intermediate shaft and steering column for alignment reference

Procedure

1. 1

   Disconnect intermediate steering shaft
   Working from inside the cab or under the dash area, locate the intermediate shaft coupling bolt connecting the steering column to the steering gear input shaft. Remove the coupling bolt completely. Use a brass punch if needed to separate the coupling, being careful not to damage the shaft. Do not allow the steering wheel to rotate once disconnected.
   Torque spec

   Coupling Bolt39 Nm (29 lb-ft)
2. 2

   Remove tie rod ends from knuckles
   Remove the cotter pins from both tie rod end castle nuts and discard. Loosen but do not fully remove the tie rod end nuts. Using a pickle fork or tie rod separator, separate the tie rod ends from the steering knuckles on both sides. Once separated, completely remove the nuts.
   Torque spec

   Tie Rod End Nut62 Nm (46 lb-ft)
3. 3

   Disconnect power steering lines
   Using flare nut wrenches to prevent rounding, carefully disconnect the pressure line and return line fittings from the steering gear box. Allow fluid to drain into the drain pan. Immediately cap or plug the lines and gear box ports to prevent contamination and further fluid loss. Remove and discard all O-rings from the fittings.
   ⚠Use flare nut wrenches to prevent rounding of hydraulic fittings
   Torque spec

   Pressure Line Fitting39 Nm (29 lb-ft)

   Power Steering Line Fittings30 Nm (22 lb-ft)
4. 4

   Support the steering gear
   Position a transmission jack or suitable support device under the steering gear box to support its weight during removal. The gear box assembly weighs approximately 30-40 lbs and is awkward to handle.
   ⚠Steering gear is heavy and mounted overhead - ensure adequate support before removing mounting bolts
5. 5

   Remove steering gear mounting bolts
   Locate the steering gear mounting bolts that secure the gear box to the front crossmember. There are typically two or four mounting bolts depending on configuration. Remove all mounting bolts completely while supporting the gear box weight.
   Torque spec

   Rack Mounting Bolts117 Nm (86 lb-ft)

   Rack Bolts117 Nm (86 lb-ft)
6. 6

   Remove steering gear from vehicle
   Carefully lower the steering gear assembly while guiding the tie rod ends through their openings in the subframe. Maneuver the assembly toward the driver's side and downward to remove it from the vehicle. The input shaft must clear the firewall area. Inspect the removed gear box for fluid leaks and damage.
   ⚠Use care when maneuvering gear box to avoid damage to brake lines, ABS sensors, and other components
7. 7

   Prepare new steering gear for installation
   Remove all protective caps and plugs from the new steering gear box. Install new O-rings on all hydraulic line fittings, lubricating them lightly with clean power steering fluid. Verify the new gear box input shaft is centered (count turns lock-to-lock and center it). Compare the new assembly with the old to verify correct application.
   ℹ️New steering gear must be centered before installation to match the locked steering wheel position
8. 8

   Install new steering gear into vehicle
   Maneuver the new steering gear assembly into position, guiding the tie rod ends through the subframe openings and aligning the input shaft with the firewall opening. Support the assembly on the jack and align the mounting bolt holes with the crossmember.
9. 9

   Install and torque mounting bolts
   Install all steering gear mounting bolts finger-tight first to ensure proper alignment. Following the sequence specified in the service manual if applicable, torque the mounting bolts in a cross pattern to ensure even clamping. Remove the support jack once all bolts are torqued.
   ℹ️Verify bolt tightening sequence with service manual to prevent gear box distortion
   Torque spec

   Rack Mounting Bolts117 Nm (86 lb-ft)

   Rack Bolts117 Nm (86 lb-ft)
10. 10

    Connect power steering hydraulic lines
    Remove protective caps from the steering gear ports. Ensure new O-rings are properly seated on the line fittings. Thread the pressure line and return line fittings into the gear box ports by hand first to prevent cross-threading. Torque the fittings to specification using flare nut wrenches.
    ⚠Start all hydraulic fittings by hand to prevent cross-threading
    Torque spec

    Pressure Line Fitting39 Nm (29 lb-ft)

    Power Steering Line Fittings30 Nm (22 lb-ft)
11. 11

    Reconnect tie rod ends to knuckles
    Clean the tie rod tapers and knuckle bores with a wire brush. Insert the tie rod ends into the steering knuckles on both sides. Install the tie rod end nuts and torque to specification. Install new cotter pins through the castle nuts and bend tabs to secure. Verify the cotter pins are properly installed and the tie rod ends have no vertical play.
    ⚠Always use new cotter pins - never reuse old pins
    Torque spec

    Tie Rod End Nut62 Nm (46 lb-ft)
12. 12

    Reconnect intermediate steering shaft
    Verify the steering wheel has not rotated and is still locked in the centered position. Align the intermediate shaft coupling with the steering gear input shaft using the alignment marks made during disassembly. Install the new coupling bolt and torque to specification. Verify the connection is secure with no play.
    ⚠️Verify steering wheel remained locked and centered throughout procedure before connecting shaft
    Torque spec

    Coupling Bolt39 Nm (29 lb-ft)
13. 13

    Fill and bleed power steering system
    Fill the power steering reservoir with Motorcraft MERCON LV ATF to the cold fill line. Start the engine and turn the steering wheel slowly lock-to-lock several times without holding at full lock. Check fluid level and add as needed. Continue bleeding until no air bubbles appear in the reservoir and the fluid level stabilizes. Check all connections for leaks.
    ⚠Do not hold steering at full lock for more than 5 seconds to prevent pump damage
    ℹ️Fluid level will drop as system fills - check frequently and add fluid as needed

Reassembly

1. Install front wheels and torque lug nuts to specification in a star pattern
2. Lower vehicle to ground and perform final torque check on wheel lug nuts
3. Remove steering wheel lock device
4. Reconnect negative battery terminal
5. Top off power steering fluid to proper hot level after system reaches operating temperature
6. Verify steering wheel is centered with wheels pointing straight ahead

Verification

• Start engine and verify no power steering fluid leaks at gear box or line connections
• Turn steering wheel lock-to-lock and verify smooth operation with no binding or unusual noises
• Verify power steering assist is functioning properly
• Check that steering wheel returns to center after turning
• Test drive vehicle at low speed in a safe area to verify proper steering function
• Verify steering wheel is centered when driving straight
• Schedule four-wheel alignment immediately - steering geometry has been disturbed
• Recheck all hydraulic connections for leaks after test drive
• Recheck power steering fluid level after test drive and top off if needed

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