Control Arm Bushing - Front Upper

Replace the front upper control arm bushings on a 2007-2013 Mercedes-Benz S65 AMG by removing the control arm assembly, pressing out old bushings, installing new bushings, and reinstalling with proper torque specifications.

Warnings

Tools required

Parts

• Front upper control arm bushing kit × 2 — Use OEM specification Mercedes-Benz bushings
• Ball joint cotter pin × 1 — Use OEM specification
• Self-locking nuts (if applicable) × 2 — Use OEM specification - replace if deformed

Preparation

1. Park vehicle on level surface and engage parking brake.
2. Loosen front wheel lug nuts while vehicle is on ground.
3. Raise front of vehicle and support securely on jack stands at manufacturer-specified jacking points.
4. Remove front wheel on side being serviced.
5. Spray all fasteners with penetrating oil and allow to soak for 10-15 minutes.
6. Have hydraulic press or specialized bushing press tool available with proper adapters before beginning disassembly.

Procedure

1. 1

   Disconnect sway bar link
   Locate the sway bar link connection to the upper control arm. Use an Allen key to hold the shaft while loosening the upper nut with a 16mm socket. Remove the sway bar link from the control arm. This provides clearance for control arm removal.
   Torque spec

   Sway Bar Link Nuts55 Nm (41 lb-ft)
2. 2

   Remove upper ball joint cotter pin
   Locate the upper ball joint where the control arm connects to the steering knuckle. Remove and discard the cotter pin from the ball joint castle nut using cotter pin pliers. Keep the area clean to avoid contaminating the ball joint boot.
   Torque spec

   Ball Joint Nut119 Nm (88 lb-ft)
3. 3

   Loosen ball joint nut and separate
   Using a 19mm socket, loosen the ball joint nut but do not remove completely - leave it threaded on by a few turns to protect threads. Use a ball joint separator or pickle fork to break the taper connection between the ball joint stud and steering knuckle. Once separated, remove the nut completely. Support the control arm to prevent it from dropping.
   ⚠The control arm may drop suddenly when the ball joint separates. Keep hands clear of pinch points.
   Torque spec

   Ball Joint Nut119 Nm (88 lb-ft)
4. 4

   Remove strut tower mounting nuts
   Access the upper strut tower mounting nuts from under the hood. Remove the engine cover if necessary for access. Use a 16mm socket to remove the three nuts securing the upper control arm mount to the strut tower. Note the position of any washers or spacers for reinstallation.
   Torque spec

   Strut Tower Nuts50 Nm (37 lb-ft)
5. 5

   Mark and remove control arm rear mounting bolts
   Mark the orientation of the control arm relative to the chassis mounting points with paint or a marker. Using an 18mm socket and breaker bar, remove the control arm mounting bolts at the rear chassis connection points. These bolts secure the bushings to be replaced. Support the control arm during removal.
   ℹ️Marking orientation ensures proper camber and caster settings during reinstallation and minimizes alignment deviation.
   Torque spec

   Control Arm Bolts165 Nm (122 lb-ft)
6. 6

   Remove control arm assembly
   With all fasteners removed, carefully maneuver the upper control arm assembly out of the wheel well. It may be necessary to pivot the steering knuckle or use a pry bar for clearance. Inspect the ball joint and control arm for wear or damage while removed.
7. 7

   Press out old bushings
   Secure the control arm in a hydraulic press or use a portable bushing press tool. Select the appropriate adapter sleeves that match the bushing outer diameter. Position the control arm so the bushing can be pressed straight out without binding. Apply steady pressure to press the old bushing out of the control arm bore. Repeat for the second bushing location. Clean the bushing bores with a wire brush and inspect for damage or deformation.
   ⚠Ensure the control arm is properly supported in the press to prevent damage. Press must be aligned straight to avoid cracking the control arm housing.
8. 8

   Install new bushings
   Apply a light coat of soapy water or approved bushing lubricant to the outer diameter of the new bushings (do not use petroleum-based lubricants). Verify the bushing orientation - some bushings have directional markings or offset voids. Position the new bushing at the control arm bore opening. Using the hydraulic press with proper adapters, press the new bushing straight into the bore until fully seated and flush. The bushing should press in evenly without cocking. Repeat for the second bushing position.
   ℹ️Bushings must be fully seated and oriented correctly. Misalignment will cause premature wear and handling issues.
9. 9

   Reinstall control arm to chassis
   Position the control arm assembly back into the mounting location, aligning it with the marks made during removal. Insert the rear mounting bolts through the new bushings and chassis brackets but do not torque yet - leave them finger tight. The control arm must be at normal ride height when final torquing occurs.
10. 10

    Attach strut tower mounting
    Align the upper control arm mount with the strut tower studs. Install any spacers or washers in their original positions. Thread on the three mounting nuts and torque to specification using a 16mm socket and torque wrench.
    Torque spec

    Strut Tower Nuts50 Nm (37 lb-ft)
11. 11

    Connect ball joint to knuckle
    Clean the ball joint stud taper and steering knuckle bore with a wire brush. Insert the ball joint stud into the steering knuckle and install the castle nut. Torque the nut to specification using a 19mm socket and torque wrench. Install a new cotter pin through the castle nut and ball joint stud, bending the ends to secure.
    ℹ️If the cotter pin hole does not align, tighten the nut further up to the next alignment point. Never loosen the nut to align the cotter pin hole.
    Torque spec

    Ball Joint Nut119 Nm (88 lb-ft)
12. 12

    Reconnect sway bar link
    Position the sway bar link onto the control arm mounting point. Install the nut and use an Allen key to hold the shaft while torquing the nut to specification with a 16mm socket and torque wrench.
    Torque spec

    Sway Bar Link Nuts55 Nm (41 lb-ft)
13. 13

    Install wheel and lower vehicle to ground
    Reinstall the wheel and hand-thread all lug nuts. Lower the vehicle until the tires just contact the ground but the suspension is not yet fully loaded. Torque the lug nuts to specification in a star pattern using a 19mm socket and torque wrench.
    Torque spec

    Wheel Lug Nuts183 Nm (135 lb-ft)
14. 14

    Torque control arm bolts at ride height
    With the vehicle at normal ride height (full weight on wheels), torque the control arm rear mounting bolts to specification using an 18mm socket and torque wrench. This is critical - bushings must be torqued at ride height to prevent premature wear and binding.
    ⚠Control arm bushing bolts MUST be torqued with vehicle weight on the suspension. Torquing while suspended will cause bushing failure and poor handling.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)

Reassembly

1. Repeat all steps for the opposite side if replacing both upper control arm bushings.
2. Reinstall any engine covers or trim panels removed for access.
3. Verify all fasteners are torqued to specification and all cotter pins are properly installed.

Verification

• Test drive the vehicle at low speed in a safe area and verify normal steering feel and no unusual noises from the suspension.
• Inspect all mounting points for proper seating and verify no looseness in the control arm.
• Schedule a professional wheel alignment immediately after this repair - camber, caster, and toe will be affected by control arm removal.
• After 50-100 miles, re-check all fastener torques to ensure nothing has loosened during initial break-in.

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