Lower Control Arm - Front

This procedure covers the removal and replacement of the front lower control arm on a 2007-2013 Mercedes-Benz S65 AMG, including ball joint separation and proper torque at ride height.

Warnings

Tools required

Parts

• Front lower control arm assembly × 1 — Use OEM specification
• Lower control arm ball joint nut × 1 — A2213320440 or equivalent
• Lower control arm frame bolts (if TTY) × 2 — Check service bulletin for TTY status

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 placed at manufacturer-specified jacking points.
4. Remove front wheel on side being serviced.
5. Spray all control arm bolts and ball joint nut with penetrating lubricant and allow to soak for 10-15 minutes.

Procedure

1. 1

   Support suspension
   Position a floor jack under the lower control arm near the ball joint to support the suspension assembly. Apply just enough pressure to take the load off the control arm but do not lift the vehicle.
2. 2

   Disconnect sway bar link
   Locate the sway bar end link connection to the lower control arm. Hold the link shaft with an Allen key to prevent rotation while removing the retaining nut. Disconnect the sway bar link from the control arm and move aside.
   Torque spec

   Sway Bar Link Nuts55 Nm (41 lb-ft)
3. 3

   Remove ball joint nut
   Remove the castle nut securing the lower ball joint to the steering knuckle. Note if a cotter pin is present and remove it first. Discard the old nut as a new one must be used during reinstallation.
   ℹ️Keep track of any shims or washers that may be present at the ball joint connection.
   Torque spec

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

   Separate ball joint from knuckle
   Using a ball joint separator or pickle fork, carefully separate the lower ball joint stud from the steering knuckle. Position the separator between the control arm and knuckle, then apply force gradually. Once separated, slowly lower the floor jack to allow the control arm to drop away from the knuckle.
   ⚠Do not strike the ball joint stud with a hammer as this can damage the stud threads or knuckle taper.
5. 5

   Mark control arm position
   Before removing frame mounting bolts, mark the position of the control arm relative to the subframe with paint or a marker. This will aid in initial positioning during installation and reduce alignment time.
6. 6

   Remove rear frame mounting bolt
   Locate the rear control arm mounting bolt that connects the control arm to the subframe. Using a breaker bar and socket, remove this bolt completely. Note that this bolt may be TTY (torque-to-yield) and should be replaced if specified by Mercedes-Benz service bulletins.
   Torque spec

   Lower Control Arm Frame Bolts125 Nm (92 lb-ft)
7. 7

   Remove front frame mounting bolt
   Remove the front control arm mounting bolt that connects the control arm to the subframe. Support the control arm as you remove the final bolt to prevent it from falling. Carefully remove the control arm from the vehicle.
   Torque spec

   Lower Control Arm Frame Bolts125 Nm (92 lb-ft)
8. 8

   Inspect and prepare mounting points
   Thoroughly clean all mounting points on the subframe using a wire brush. Inspect the ball joint taper seat in the steering knuckle for damage or excessive wear. Check subframe mounting holes for elongation or damage. Apply a light coat of anti-seize to the threads of the new frame mounting bolts if they are not pre-coated.
9. 9

   Install new control arm
   Position the new lower control arm into the subframe mounting points, aligning with the marks made during removal. Insert both front and rear frame mounting bolts but only hand-tighten them at this stage. Ensure bushings are properly seated in their mounting brackets.
   ⚠Do NOT torque frame mounting bolts at this time. They must be torqued at ride height in a later step.
10. 10

    Connect ball joint to knuckle
    Raise the control arm using the floor jack to align the ball joint stud with the hole in the steering knuckle. Insert the stud through the knuckle and install the NEW ball joint nut. Torque the nut to specification.
    Torque spec

    Ball Joint Nut119 Nm (88 lb-ft)
11. 11

    Reconnect sway bar link
    Reconnect the sway bar end link to the lower control arm. Hold the link shaft with an Allen key and torque the retaining nut to specification.
    Torque spec

    Sway Bar Link Nuts55 Nm (41 lb-ft)
12. 12

    Reinstall wheel and prepare for ride height torque
    Reinstall the wheel and hand-tighten the lug nuts. Lower the vehicle onto alignment ramps, wheel dollies, or safely onto the ground to achieve normal ride height with vehicle weight on the suspension. If using ramps or the ground, ensure the vehicle cannot roll.
13. 13

    Torque control arm frame bolts at ride height
    With the vehicle at ride height and suspension loaded, torque both the front and rear lower control arm frame mounting bolts to specification in the sequence: rear bolt first, then front bolt. This critical step ensures proper bushing alignment and longevity.
    ⚠️Torquing these bolts with suspension unloaded will pre-load the bushings incorrectly and cause premature failure. Vehicle weight MUST be on wheels.
    Torque spec

    Lower Control Arm Frame Bolts125 Nm (92 lb-ft)
14. 14

    Final wheel installation
    If vehicle was lowered to ground for torque procedure, raise and support again if needed. Torque wheel lug nuts to specification in a star pattern.
    Torque spec

    Wheel Lug Nuts183 Nm (135 lb-ft)

Reassembly

1. Ensure all fasteners are torqued to specification and no tools or parts are left in the wheel well.
2. Lower vehicle to ground and perform final lug nut torque verification.
3. Bounce the front suspension several times to settle components before driving.

Verification

• Verify all bolts and nuts are properly torqued, especially control arm frame bolts which were torqued at ride height.
• Check for any unusual noises when bouncing the suspension or turning the steering wheel lock to lock.
• Test drive at low speed and verify no clunking, knocking, or handling abnormalities.
• Schedule a professional four-wheel alignment immediately after completing this repair, as suspension geometry has been altered.

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

Chasing one of these codes and not sure which part is guilty? Ask a master mechanic about YOUR car →

More procedures for this vehicle