Ball Joints - Upper and Lower

Complete replacement of upper and lower ball joints on both front wheels, including control arm disassembly and reassembly with specified torque values.

Warnings

Tools required

Parts

• Upper ball joint × 2 — Use OEM specification
• Lower ball joint × 2 — Use OEM specification
• Cotter pins (upper ball joint) × 2 — Use OEM specification
• Cotter pins (lower ball joint) × 2 — Use OEM specification
• Pinch bolt (if reusing is not recommended) × 2 — Use OEM specification

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 both front wheels.
5. Apply penetrating oil to all ball joint nuts, pinch bolts, and control arm mounting bolts. Allow to soak while gathering tools.

Procedure

1. 1

   Remove wheel speed sensor and brake line brackets
   Disconnect the wheel speed sensor electrical connector. Remove any brake line brackets or clips attached to the control arm or knuckle to provide clearance for control arm removal. Note the routing for reinstallation.
2. 2

   Disconnect sway bar link
   Locate the sway bar end link connection (verify attachment point on this platform — upper arm, lower arm, or knuckle — against DB9 OEM documentation, and note it for consistent reinstallation). Counter-hold the ball stud shaft (Allen key, Torx bit, or wrench flat as applicable to this platform) to prevent rotation, then remove the nut securing the end link. Swing the end link away from the suspension arm.
   Torque spec

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

   Remove upper ball joint cotter pin and nut
   Locate the upper ball joint connection at the top of the steering knuckle (vertical link). Remove the upper ball joint retaining nut. Note: verify whether this platform uses a self-locking nut or a castellated nut with cotter pin before discarding any hardware. Do not separate the joint yet. Note: Locate the upper ball joint connection at the top of the steering knuckle. If equipped with a cotter pin, remove and discard it; otherwise note this platform may use a self-locking nut. Remove the upper ball joint nut completely. Do not separate the joint yet. Verify fastener type against DB9 service documentation.
   Torque spec

   Upper Ball Joint Nut119 Nm (87.8 lb-ft)
4. 4

   Remove lower ball joint cotter pin and nut
   Locate the lower ball joint connection at the bottom of the steering knuckle. If equipped with a cotter pin, remove and discard it; otherwise note this platform may use a self-locking nut. Remove the lower ball joint nut completely. Do not separate the joint yet. Verify fastener type against DB9 service documentation. Note: Locate the lower ball joint connection at the bottom of the steering knuckle (vertical link). Remove the lower ball joint retaining nut. Note: verify whether this platform uses a self-locking nut or a castellated nut with cotter pin before discarding any hardware. Do not separate the joint yet.
   Torque spec

   Lower Ball Joint Nut119 Nm (88 lb-ft)
5. 5

   Separate upper ball joint from knuckle
   Using a ball joint separator or pickle fork, carefully separate the upper ball joint taper from the steering knuckle. Position the separator between the control arm and knuckle, then strike or tighten to break the taper fit. The knuckle will now pivot on the lower ball joint. Note: Ball joint will release suddenly. Support the knuckle assembly to prevent damage to the brake hose, wheel speed sensor, or other brake components.
   ⚠Ball joint will release suddenly. Support the knuckle assembly to prevent damage to CV boot or brake components.
6. 6

   Separate lower ball joint from knuckle
   Using a ball joint separator, separate the lower ball joint taper from the bottom of the steering knuckle. Apply separator force between the lower control arm and knuckle. Once separated, support the knuckle assembly and carefully move it aside. Secure with wire or bungee cord if needed to prevent stress on the brake hose and wheel speed sensor wiring. Note: Do not allow knuckle to hang by the brake hose or wheel speed sensor wiring. Support the assembly properly.
   ⚠Do not allow knuckle to hang by CV axle boot or brake hose. Support the assembly properly.
7. 7

   Remove upper control arm mounting bolts
   Support the upper control arm with a jack or stand. Locate the upper control arm mounting bolts at the frame/subframe attachment point. Remove the 2 mounting bolts securing the upper control arm to the chassis. Carefully lower and remove the upper control arm from the vehicle.
   Torque spec

   Control Arm Bolts105 Nm (77 lb-ft)
8. 8

   Remove lower control arm mounting bolts
   Support the lower control arm with a jack to manage spring tension if present. Locate the lower control arm mounting bolts at the frame/subframe attachment points. Remove the mounting bolts (typically front and rear pivot points). Carefully lower and remove the lower control arm from the vehicle, watching for any remaining spring tension. Note: Verify the spring/damper mounting location for this platform before removing control arm bolts. On the DB9 the coil-over unit mounts to the upper arm/body; support the suspension and relieve any spring load through the damper mount before disconnecting arm fasteners.
   ⚠Lower control arm may be under coil spring tension depending on suspension design. Support with jack and lower carefully.
   Torque spec

   Control Arm Bolts105 Nm (77 lb-ft)
9. 9

   Press out old upper ball joint
   On the DB9 the upper ball joint is integral to the forged aluminum control arm and is NOT a serviceable pressed-in component. The complete upper control arm assembly must be replaced as a unit. Do not attempt to press the ball joint out, as this will destroy the aluminum arm. Verify against OEM documentation.
10. 10

    Press in new upper ball joint
    The upper ball joint is integral to the control arm on the DB9, so no pressing operation is required. Install the complete new upper control arm assembly (with integral ball joint) per the installation steps. Verify against OEM documentation.
11. 11

    Press out old lower ball joint
    On the DB9 the lower ball joint is integral to the forged aluminum control arm and is NOT a serviceable pressed-in component. The complete lower control arm assembly must be replaced as a unit. Do not attempt to press the ball joint out, as this will destroy the aluminum arm. Verify against OEM documentation.
12. 12

    Press in new lower ball joint
    The lower ball joint is integral to the control arm on the DB9, so no pressing operation is required. Install the complete new lower control arm assembly (with integral ball joint) per the installation steps. Verify against OEM documentation.
13. 13

    Install lower control arm
    Position the lower control arm with new ball joint into the chassis mounting points. Install the control arm mounting bolts finger-tight only at this stage. Do not torque yet, as these bolts must be torqued with vehicle weight on wheels.
14. 14

    Install upper control arm
    Position the upper control arm with new ball joint into the chassis mounting points. Install the upper control arm mounting bolts finger-tight only at this stage. Do not torque yet, as these bolts must be torqued with vehicle weight on wheels.
15. 15

    Connect ball joints to steering knuckle
    Remove any support from the knuckle assembly. Guide the lower ball joint stud into the steering knuckle bottom and install the retaining nut. Tighten to specification. Guide the upper ball joint stud into the steering knuckle top and install the retaining nut. Tighten to specification. If the platform uses castellated nuts, install new cotter pins ensuring proper alignment with the nut slots and bend the ends to secure; if self-locking nuts are used, install new self-locking nuts. Verify fastener type against DB9 OEM documentation.
    Torque spec

    Upper Ball Joint Nut119 Nm (87.8 lb-ft)

    Lower Ball Joint Nut119 Nm (88 lb-ft)
16. 16

    Reconnect sway bar link
    Position the sway bar end link to the lower control arm mounting point. Install the nut while holding the ball stud shaft with an Allen key to prevent rotation. Torque to specification.
    Torque spec

    Sway Bar Link Nuts55 Nm (41 lb-ft)
17. 17

    Reinstall wheel speed sensor and brake line brackets
    Reinstall any brake line brackets or clips to the control arm or knuckle in their original positions. Reconnect the wheel speed sensor electrical connector. Ensure all wiring is properly routed and secured away from moving suspension components.
18. 18

    Repeat for opposite side
    Perform steps 1 through 17 on the opposite front wheel, replacing both upper and lower ball joints on that side.
19. 19

    Install wheels and lower vehicle
    Install both front wheels and hand-tighten lug nuts in a star pattern. Lower vehicle until tires just contact the ground but vehicle weight is still supported by jack stands. Torque wheel lug nuts to specification in a star pattern. Fully lower vehicle to the ground.
    Torque spec

    Wheel Lug Nuts89 Nm (66 lb-ft)
20. 20

    Final torque control arm bolts with vehicle weight on wheels
    With vehicle on the ground and suspension at ride height, torque all control arm mounting bolts (both upper and lower arms, both sides) to specification. This critical step ensures bushings are not pre-loaded in the wrong position, which would cause premature wear.
    ⚠️Control arm bolts MUST be torqued with vehicle weight on wheels. Failure to do so will cause bushing failure and handling issues.
    Torque spec

    Control Arm Bolts105 Nm (77 lb-ft)

Reassembly

1. Control arm mounting bolts must be torqued with vehicle weight on wheels at normal ride height.
2. All cotter pins must be new and properly installed with ends bent to prevent backing out.
3. Verify all electrical connectors and brake line brackets are securely reinstalled.
4. If pinch bolts were used in this application, they must be replaced with new bolts per torque specification.

Verification

• With vehicle on ground, bounce each front corner and verify no clunking or abnormal noises from ball joints.
• Verify all cotter pins are properly installed and secured in upper and lower ball joints on both sides.
• Turn steering wheel lock-to-lock and verify smooth operation with no binding or interference.
• Visually inspect that all fasteners are tight and no tools or parts were left in the wheel wells.
• Test drive vehicle at low speed in a safe area, checking for proper steering response and absence of suspension noise.
• Schedule a professional alignment as ball joint replacement affects suspension geometry.

More procedures for this vehicle