Front Struts - Pair

Complete replacement of both front strut assemblies on a 2019 Mercedes-Benz G-Class with 4.0L Turbo V8, including disconnection of steering knuckle, sway bar links, and upper mounting hardware.

Warnings

Tools required

Parts

• Front strut assembly (complete) × 2 — Use OEM specification
• Strut tower mounting nuts (if reusable nuts are damaged) × 6 — Use OEM specification
• Strut-to-knuckle bolts and nuts × 4 — Use OEM specification
• Thread locking compound (medium strength) × 1 — Loctite 243 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen front wheel lug nuts approximately one turn while vehicle is on ground
3. Raise front of vehicle with floor jack and support securely on jack stands at manufacturer-specified jacking points on frame rails
4. Remove both front wheels completely and set aside
5. Spray all suspension fasteners with penetrating oil and allow 15-20 minutes to soak
6. Place a floor jack under the lower control arm on the side being serviced to support suspension weight

Procedure

1. 1

   Access and disconnect ABS wheel speed sensor
   Locate the ABS wheel speed sensor wire routing along the strut body. Remove the mounting clip or bracket securing the sensor wire to the strut housing. Disconnect the electrical connector if it routes through the strut mounting area. Carefully separate the wire from any additional clips to prevent damage during strut removal.
2. 2

   Disconnect sway bar end link from strut
   Locate the sway bar end link connection point on the strut assembly. Hold the ball stud with the appropriate hex bit (verify size against factory spec) to prevent spinning, then remove the securing nut with the correctly sized wrench (verify size). Separate the end link from the strut mounting point. If the ball joint spins, use locking pliers on the ball stud to hold it steady.
   Torque spec

   Sway Bar Link70 Nm (52 lb-ft)
3. 3

   Disconnect brake line bracket from strut
   Locate the brake line bracket mounted to the strut body. Remove the fastener securing the bracket to the strut (typically a Torx or hex bolt). Do not disconnect the brake line itself—simply unbolt the bracket to allow clearance for strut removal. Support the brake line to prevent stress on the connection.
4. 4

   Remove strut-to-knuckle pinch bolts
   Locate the lower shock absorber mounting bolt securing the shock to the bracket on the front axle housing. Remove the lower shock mounting fastener. Use a breaker bar and appropriate sockets to remove both bolts completely. Note the orientation of the bolts for reinstallation. The knuckle may be tight on the strut—use a dead blow hammer to tap the knuckle rearward if needed to separate after bolts are removed.
   ⚠Ensure the floor jack is supporting the lower control arm before removing these bolts. The suspension will drop slightly when bolts are removed.
5. 5

   Separate steering knuckle from strut
   This step does not apply to the G-Class solid front axle. After removing the lower shock bolt, simply free the lower shock eye from its mounting bracket on the axle housing. If seized, tap the knuckle with a dead blow hammer while applying outward pressure. Do not allow the knuckle to hang by the brake line—support it with a bungee cord or wire hung from the frame.
6. 6

   Access upper strut tower mounting nuts
   Open the hood and locate the strut tower on the inner fender well. Remove the plastic cover or trim panel covering the strut tower mounting points (typically secured with push clips or Torx fasteners). Locate the upper shock absorber mount on the frame bracket. The upper shock end is typically secured by a single retaining nut on a stud (or an eye/bolt), not a three-nut strut plate.
7. 7

   Remove upper strut tower mounting nuts
   While supporting the shock absorber, remove the upper shock retaining nut (verify socket size against factory spec). Note washer/bushing arrangement on the upper stud. Keep track of any washers or spacers under the nuts. Do not allow the strut to drop suddenly—lower it carefully as you remove the final nut.
   ⚠The strut assembly is heavy (approximately 25-30 lbs). Support it during removal to prevent dropping.
   Torque spec

   Strut Tower Nuts55 Nm (40 lb-ft)
8. 8

   Remove strut assembly from vehicle
   Carefully guide the strut assembly downward and outward through the lower control arm area. Maneuver it clear of the brake components, ABS sensor wiring, and wheel well. Set the old strut aside in a safe location. Repeat steps 1-8 for the opposite side if not already completed.
9. 9

   Prepare new strut assembly for installation
   Unpack the new strut assembly and verify it matches the original (mounting points, length, and configuration). No spring transfer or spring compressor is required for shock replacement on the G-Class, since the coil spring is separate from the shock absorber. Verify new shock matches original length and mounting configuration. Ensure the upper mount is properly oriented and all hardware is present. Apply a thin coat of anti-seize to the strut shaft threads if exposed.
10. 10

    Install new strut into strut tower
    Guide the new strut assembly up into position, aligning the upper mounting studs with the holes in the strut tower. Ensure any locating features are properly seated. Install the three upper mounting nuts hand-tight first to hold the strut in position. Do not fully torque at this stage.
11. 11

    Connect strut to steering knuckle
    Raise the floor jack under the lower control arm slightly to bring the steering knuckle into alignment with the strut shaft. Guide the strut shaft into the knuckle pinch slot, ensuring proper engagement. The knuckle should slide fully onto the strut shaft. Install both strut-to-knuckle bolts with nuts, inserting them in the same orientation as removal. Start both bolts hand-tight before fully tightening.
12. 12

    Torque strut-to-knuckle bolts
    Using a torque wrench, tighten both strut-to-knuckle bolts to specification. Torque the nut side while holding the bolt head to prevent spinning. Apply torque in a cross pattern (alternate between bolts) to ensure even seating.
13. 13

    Torque upper strut tower mounting nuts
    From under the hood, torque all three upper strut tower mounting nuts to specification in a star pattern to ensure even loading of the mount. Verify all three nuts are properly seated and torqued.
    Torque spec

    Strut Tower Nuts55 Nm (40 lb-ft)
14. 14

    Reconnect sway bar end link
    Connect the sway bar end link ball stud to the mounting point on the strut. Install the retaining nut and hold the ball stud with a hex bit to prevent spinning. Torque the nut to specification using a torque wrench.
    Torque spec

    Sway Bar Link70 Nm (52 lb-ft)
15. 15

    Reconnect brake line bracket and ABS sensor
    Reinstall the brake line bracket to the strut body using the original fastener. Torque the brake line bracket bolt to the factory-specified value (verify in service documentation). Reconnect the ABS wheel speed sensor wiring, securing all clips and connectors along the strut. Ensure no wires are pinched or stretched.
16. 16

    Reinstall wheel and lower vehicle
    Reinstall the wheel onto the hub, starting all lug nuts by hand to prevent cross-threading. Snug the lug nuts in a star pattern but do not fully torque yet. Repeat steps 10-16 for the opposite side if not already completed. Once both sides are complete, carefully lower the vehicle to the ground and remove jack stands.
17. 17

    Final torque wheel lug nuts
    With the vehicle on the ground and full weight on the suspension, torque all wheel lug nuts to specification in a star pattern using a torque wrench. Verify each lug nut is properly torqued.
    Torque spec

    Wheel Lug Nuts142.4 Nm (105 lb-ft)
18. 18

    Reinstall strut tower covers
    Under the hood, reinstall any plastic covers or trim panels over the strut tower mounting areas. Ensure all clips and fasteners are properly seated.

Reassembly

1. All fasteners must be torqued to specification—suspension fasteners are safety-critical and improper torque can cause failure
2. Verify all electrical connections (ABS sensor) are fully seated and properly routed
3. Check that brake lines have adequate slack and are not under tension or at risk of chafing
4. Lower control arm jack support should be removed only after all suspension components are fully installed and torqued

Verification

• Bounce each corner of the vehicle firmly—struts should dampen motion smoothly without clunking or excessive rebound
• Verify no fluid leaks from new strut assemblies
• Check that all wheel lug nuts are torqued to specification
• Verify ABS warning light does not illuminate on instrument cluster (may require short test drive to self-check)
• Test drive at low speed in a safe area—listen for any clunking, rattling, or abnormal sounds from suspension
• Verify steering returns to center properly and vehicle tracks straight (within limits of alignment state)
• Schedule four-wheel alignment immediately—suspension geometry has been disturbed and alignment is mandatory for safe operation and tire wear

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