Knuckle/Spindle - Front

This procedure covers removal and installation of the front steering knuckle/spindle assembly on a 2009 Aston Martin DB9, including separation from suspension components and wheel hub.

Warnings

Tools required

Parts

• Front steering knuckle/spindle assembly × 1 — Use OEM specification
• Axle nut × 1 — Replace - single-use torque-to-yield
• Upper ball joint castle nut × 1 — Replace if cotter pin damaged
• Lower ball joint castle nut × 1 — Replace if cotter pin damaged
• Tie rod end castle nut × 1 — Replace if cotter pin damaged
• New cotter pins × 3 — Assorted sizes

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 under manufacturer-specified jacking points.
4. Remove front wheel completely.
5. Spray penetrating oil on all fasteners to be removed and allow to soak for 10-15 minutes.

Procedure

1. 1

   Remove axle nut
   NOTE: The 2009 Aston Martin DB9 is rear-wheel drive and has NO front axle shaft or front axle center nut. The front hub is a sealed, non-driven bearing unit integral to the knuckle. Skip any axle-nut removal — this step does not apply. Note: NOTE: This is a rear-wheel-drive vehicle — the front hub is a non-driven wheel bearing unit and there is NO front axle center nut. Verify the hub/bearing retention method against the factory service manual (often a bolted hub carrier or pressed/integral bearing) before proceeding; do not attempt to remove a non-existent axle nut. Note: Front hub/bearing carrier bolt torque specification for 2009 Aston Martin DB9 (no front axle nut exists on this RWD platform)
2. 2

   Remove brake caliper
   Locate the two caliper mounting bolts on the rear of the caliper bracket. These are typically large E-Torx fasteners. Remove both bolts and carefully lift the caliper assembly off the rotor. Do NOT let the caliper hang by the brake hose. Support it with a caliper hanger or secure it to the suspension with wire. Do not disconnect the brake line unless caliper removal is also required.
3. 3

   Remove brake rotor
   If the rotor has retaining screws, remove them using appropriate Torx bit. Slide the brake rotor off the hub. If rotor is seized to the hub, use penetrating oil and light taps with a rubber mallet on the rotor face (alternating sides) to break it free. Do not damage the hub surface.
4. 4

   Disconnect ABS wheel speed sensor
   Locate the ABS wheel speed sensor for this corner. Verify its type and mounting (active encoder-ring sensor vs. passive bore sensor) against the factory service manual before removal. Disconnect the electrical connector, remove any mounting fastener, and carefully extract the sensor, noting that the encoder ring may be integral to the sealed hub bearing. Set aside in a clean location.
5. 5

   Disconnect tie rod end
   Locate the tie rod end where it connects to the steering arm on the knuckle. Remove the cotter pin and back off the castle nut (do not remove completely yet). Use a press-type ball joint/tie rod separator (puller) to break the taper between the tie rod end and knuckle. Avoid a pickle fork as it will damage the boot if the component is to be reused. Once separated, remove the castle nut completely and withdraw the tie rod end stud from the knuckle.
6. 6

   Disconnect upper ball joint
   Access the upper ball joint nut at the top of the knuckle where the upper control arm connects. Remove the cotter pin. Use a wrench to loosen the castle nut but leave it threaded on a few turns to protect the stud threads. Position a ball joint separator between the control arm and knuckle, then apply force to break the taper joint. Once separated, remove the nut completely and separate the upper control arm from the knuckle.
   Torque spec

   Upper Ball Joint Nut60 Nm (44 lb-ft)
7. 7

   Disconnect lower ball joint
   Locate the lower ball joint connection at the bottom of the knuckle where the lower control arm attaches. Remove the cotter pin and loosen the castle nut, leaving it threaded on several turns. Use a ball joint separator to break the taper between the lower control arm and knuckle. Remove the castle nut and separate the lower control arm from the knuckle. The knuckle is now retained only by the upper/lower ball joints and tie rod (already disconnected); there is NO front axle shaft on this RWD vehicle.
   Torque spec

   Lower Ball Joint Nut65 Nm (48 lb-ft)
8. 8

   Disconnect strut-to-knuckle bolts
   NOTE: The 2009 Aston Martin DB9 uses a double-wishbone front suspension with a coil-over damper mounted to the lower control arm, NOT a MacPherson strut. There are no strut-to-knuckle clamp bolts. Verify suspension architecture against the factory service manual before proceeding; with both ball joints disconnected, the knuckle is already free of the suspension. With both ball joints and the tie rod already disconnected, the knuckle is free of the suspension; there are no strut-to-knuckle bolts to remove on this double-wishbone platform. Note: NOTE: The 2009 Aston Martin DB9 uses a double-wishbone front suspension (upper and lower control arms with a separate coil-over damper), not a MacPherson strut. The knuckle is located solely by the upper and lower ball joints and tie rod — there are no strut-to-knuckle clamp bolts. Verify the suspension configuration against the factory service manual; if no strut-to-knuckle fasteners exist, omit this step. The damper lower mount typically attaches to the lower control arm, not the knuckle.
   Torque spec

   Strut Bolts85 Nm (63 lb-ft)
9. 9

   Remove knuckle from axle shaft
   With all mounting points disconnected, the knuckle assembly should now be free. With all mounting points disconnected, the knuckle assembly should now be free. On this RWD vehicle the front hub is a non-driven sealed bearing unit — there is NO front axle/driveshaft. Carefully remove the knuckle assembly from the vehicle once the ball joints are separated. Once clear, remove the knuckle assembly completely from the vehicle. Note: Carefully pull the knuckle outward away from the vehicle. Because this is a rear-wheel-drive vehicle, the front hub is a non-driven wheel bearing unit — there is no front axle shaft or splines to disengage.
10. 10

    Inspect and prepare new knuckle
    Inspect the new or replacement knuckle for any shipping damage. Check that the hub bearing rotates smoothly if the assembly includes a pre-installed bearing. Clean the hub/spindle mating surfaces and ball joint taper seats. There is no front axle shaft or splines on this RWD vehicle. Clean all ball joint taper seats and the tie rod taper seat on the new knuckle. Verify that all mounting holes are clear of debris.
11. 11

    Install knuckle onto axle shaft
    NOTE: There is no front axle shaft on this RWD vehicle. Install the new knuckle assembly by reattaching it to the upper and lower ball joints; there are no axle splines to engage. Note: Position the new knuckle assembly to the ball joint tapers and tie rod. Since this is a RWD vehicle, there is no front axle shaft or splines to engage — simply align the knuckle to the upper and lower ball joint studs.
12. 12

    Connect strut to knuckle
    NOTE: This step does not apply to the DB9 double-wishbone front suspension, which has no strut-to-knuckle bolts. Reattachment of the knuckle is accomplished through the upper and lower ball joints in the following steps. Verify against the factory service manual. Note: If the suspension configuration confirmed in removal uses no strut-to-knuckle fasteners (double-wishbone layout), skip this step. Otherwise, align the knuckle with the mating bracket, matching any alignment marks noted during disassembly, insert the bolts, and torque to the factory specification.
    Torque spec

    Strut Bolts85 Nm (63 lb-ft)
13. 13

    Connect lower ball joint
    Position the lower control arm ball joint stud into the lower knuckle bore. Install the new castle nut and tighten to specification. Continue tightening until the castle nut slots align with the stud cotter pin hole (do not back off to align). Install a new cotter pin and bend the ends to secure.
    Torque spec

    Lower Ball Joint Nut65 Nm (48 lb-ft)
14. 14

    Connect upper ball joint
    Insert the upper control arm ball joint stud into the upper knuckle bore. Install the new castle nut and tighten to specification. Align the castle nut slots with the cotter pin hole by continuing to tighten (never loosen to align). Install a new cotter pin and secure properly.
    Torque spec

    Upper Ball Joint Nut60 Nm (44 lb-ft)
15. 15

    Connect tie rod end
    Insert the tie rod end stud into the steering arm of the knuckle. Install the new castle nut and tighten to specification per the vehicle service manual. Align castle nut slots with the cotter pin hole and install a new cotter pin. Bend the ends to secure.
16. 16

    Install ABS wheel speed sensor
    Clean the sensor bore in the knuckle with a clean cloth. Apply a small amount of anti-seize to the sensor body (avoid the tip). Insert the ABS sensor into the knuckle bore and install the mounting fastener, tightening securely but not over-torquing. Reconnect the electrical connector until it clicks into place.
17. 17

    Install brake rotor and caliper
    Slide the brake rotor onto the hub, aligning any guide holes. If retaining screws were present, install them. Position the brake caliper over the rotor and align the mounting holes. Install both caliper mounting bolts and torque to specification per the vehicle service manual.
18. 18

    Install new axle nut
    NOTE: This step does not apply. The 2009 DB9 has no front axle shaft or axle nut; the front hub bearing is a sealed unit. Omit any axle-nut installation. Note: NOTE: This RWD vehicle has no front axle nut. Reinstall and torque the front hub/bearing retention fasteners (e.g., hub carrier bolts) per the factory service manual specification. There is no driveshaft nut to stake on the front corner. Note: Confirm the front hub/bearing carrier bolt retention and torque method for the 2009 Aston Martin DB9 (no front axle nut exists on this RWD platform)
19. 19

    Install wheel and lower vehicle
    Mount the wheel onto the hub, aligning the lug bolt holes. Install all lug nuts and hand-tighten in a star pattern. Lower the vehicle until the tire just touches the ground but weight is still on the jack stands. Torque the lug nuts to specification in a star pattern. Fully lower the vehicle and remove jack stands.
    Torque spec

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

    Final torque check with vehicle weight on ground
    With the vehicle weight now fully on the suspension, verify that all control arm mounting bolts (if any were disturbed) are torqued to specification. This is critical as suspension bushings must be torqued at ride height to prevent premature wear.
    Torque spec

    Control Arm Bolts100 Nm (74 lb-ft)

Reassembly

1. Reassembly follows removal in reverse order as detailed in the numbered steps above.
2. Always use new single-use fasteners (axle nut, castle nuts if deformed) and new cotter pins.
3. Ensure all ball joint tapers are clean and properly seated before torquing.
4. Verify ABS sensor connector is fully engaged and sensor is properly seated.
5. After vehicle is lowered, bounce the front suspension several times to settle components before final torque verification.

Verification

• Start the engine and verify no ABS warning light appears on the instrument cluster.
• Turn the steering wheel lock-to-lock while stationary and verify smooth operation with no binding or unusual noise.
• Test drive the vehicle at low speed in a safe area, checking for proper steering response and no pulling to either side.
• After test drive, re-check the axle nut torque and all ball joint castle nuts for proper tightness.
• Verify no unusual tire wear patterns develop after 50-100 miles. Have a professional alignment performed if the vehicle pulls or steering wheel is off-center.

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