Radius Arm

Replacement of the front radius arm (lower control arm) on a 2017 Maserati Levante, including disconnection of associated suspension components and proper torque specification procedures.

Warnings

Tools required

Parts

• Front radius arm (lower control arm) × 1 — Use OEM specification
• Ball joint cotter pin × 1 — Use OEM specification
• Control arm mounting hardware kit × 1 — Use OEM specification if hardware is damaged

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen wheel lug nuts while vehicle is on ground
3. Raise front of vehicle and support securely on jack stands under manufacturer-specified jacking points
4. Remove front wheel on affected side
5. Apply penetrating lubricant to all fasteners to be removed and allow to soak for 10-15 minutes
6. Inspect radius arm and associated components for damage

Procedure

1. 1

   Disconnect sway bar link
   Locate the sway bar link connection at the lower control arm. Use a 6mm Allen key to hold the shaft while removing the sway bar link nut with appropriate socket. Disconnect the link from the control arm and secure out of the way.
   Torque spec

   Sway Bar Link64 Nm (47 lb-ft)
2. 2

   Remove ball joint cotter pin
   Locate the ball joint where it connects to the steering knuckle at the outer end of the radius arm. Straighten and remove the cotter pin using pliers or punch and hammer. Discard the old cotter pin as a new one must be installed during reassembly.
3. 3

   Remove ball joint castle nut
   Using a 21mm socket, remove the castle nut from the ball joint stud. Do not fully remove the nut until the ball joint taper is broken to prevent sudden separation.
4. 4

   Separate ball joint from knuckle
   Use a ball joint separator or pickle fork to break the taper between the ball joint stud and steering knuckle. Position the separator tool properly to avoid damaging the ball joint boot. Once taper is broken, remove the castle nut completely and lower the control arm away from the knuckle.
5. 5

   Support lower suspension
   Position a floor jack under the lower control arm near the ball joint area to support the weight of the suspension assembly. This prevents strain on other components and makes removal easier. Raise jack just enough to take the load.
6. 6

   Remove front control arm mounting bolt
   Locate the front mounting bolt that secures the radius arm to the front subframe. Use a breaker bar and appropriate socket to remove this bolt. Note the position and orientation of any washers or bushings for reinstallation.
7. 7

   Remove rear control arm mounting bolt
   Locate the rear mounting bolt that secures the radius arm to the rear mounting point on the subframe. Remove this bolt completely using a breaker bar and socket. The control arm should now be free from the vehicle.
8. 8

   Remove radius arm assembly
   Carefully lower the floor jack and maneuver the radius arm out of the vehicle. Inspect all mounting points and bushings on the subframe for damage or excessive wear. Clean mounting surfaces with wire brush if necessary.
9. 9

   Install new radius arm
   Position the new radius arm into place, aligning the mounting holes with the subframe. Insert both front and rear mounting bolts by hand but do NOT tighten at this time. Ensure all bushings are properly seated and aligned.
10. 10

    Connect ball joint to knuckle
    Raise the outer end of the control arm using the floor jack and align the ball joint stud with the hole in the steering knuckle. Install the castle nut onto the ball joint stud and tighten to specification. Ensure the cotter pin holes in the stud align with a castle nut slot. Install new cotter pin and bend ends to secure.
    Torque spec

    Ball Joint Nut92 Nm (68 lb-ft)
11. 11

    Reconnect sway bar link
    Connect the sway bar link to the control arm. Hold the shaft with a 6mm Allen key while tightening the nut to specification.
    Torque spec

    Sway Bar Link64 Nm (47 lb-ft)
12. 12

    Install wheel and lower vehicle
    Install the wheel and hand-tighten the lug nuts in a star pattern. Lower the vehicle until the tire just contacts the ground but the full weight is still on the jack stands. This positions the suspension at ride height for final torque of control arm bolts.
13. 13

    Torque control arm bolts at ride height
    With vehicle weight now on the wheels (suspension at normal ride height), torque both the front and rear control arm mounting bolts to specification. This is critical - torquing these bolts with the suspension hanging will cause premature bushing failure.
    Torque spec

    Control Arm Bolts165 Nm (122 lb-ft)
14. 14

    Final wheel installation
    Fully lower the vehicle to the ground and remove jack stands. Torque wheel lug nuts to specification in a star pattern using a torque wrench.
    Torque spec

    Wheel Lug Nuts142 Nm (105 lb-ft)

Reassembly

1. Always use a new cotter pin on the ball joint castle nut
2. Control arm mounting bolts MUST be torqued with vehicle weight on wheels at ride height
3. Verify sway bar link shaft is held stationary with Allen key during final tightening
4. Inspect all rubber bushings for proper seating and alignment after installation

Verification

• Visually inspect all connections and verify all fasteners are properly torqued
• Check that new cotter pin is properly installed and bent on ball joint
• Test drive vehicle at low speed and verify no unusual noises or handling issues
• Perform front wheel alignment at qualified facility as suspension geometry has been altered
• After 50-100 miles, re-check all fastener torque specifications

More procedures for this vehicle