Engine Mount - Rear

Replacement of the rear engine mount on a 2009 Aston Martin DB9 6.0L V12, requiring partial exhaust removal, transmission support, and engine lift to access the mount assembly.

Warnings

Tools required

Parts

• Rear engine mount assembly × 1 — Use OEM specification
• Exhaust flange gaskets (if disturbed) × 2 — Use OEM specification

Preparation

1. Ensure vehicle is on a level surface with adequate overhead clearance for engine support equipment
2. Allow engine and exhaust system to cool completely (minimum 3 hours after operation)
3. Disconnect negative battery cable and secure away from terminal
4. Raise vehicle on lift to comfortable working height with sufficient clearance underneath
5. Remove engine undertray panels using Torx fasteners
6. Apply penetrating oil to all exhaust flange bolts and allow to soak for 15-20 minutes

Procedure

1. 1

   Support the engine from above
   Install an engine support bar across the engine bay or position an adjustable engine hoist with load leveler. Attach support chains or straps to the designated engine lifting points as specified in Aston Martin documentation (do not improvise attachment points). Apply slight upward tension to take minimal load off the mounts, but do not lift the engine yet. Verify the support is secure and balanced before proceeding. Note: Attach support chains or straps to the designated engine lifting points (verify locations against OEM documentation before applying load).
2. 2

   Remove rear exhaust sections for access
   Working from underneath, locate the exhaust clamp or flange connection point forward of the rear mufflers (verify exact location against OEM documentation). Remove the flange bolts connecting the center section to the rear section (verify exact bolt count and size against OEM documentation). Support the rear exhaust sections and carefully lower them away from the vehicle to provide clearance for mount access. Set aside on protected surface. Note: Working from underneath, locate the exhaust clamp or flange connection point forward of the rear mufflers (verify exact location). Remove the flange bolts connecting the center section to the rear section (verify exact bolt count and size against OEM documentation). Support the rear exhaust sections and carefully lower them away from the vehicle to provide clearance for mount access. Set aside on protected surface.
3. 3

   Position transmission support
   Place a transmission jack or adjustable support stand underneath the rear of the engine / torque tube interface area to stabilize driveline movement. Raise the jack until it just contacts the structure without applying lifting force. This will prevent excessive driveline movement when the rear mount is removed. Verify correct lift point against factory service documentation for the DB9 transaxle layout. Note: Note that the DB9 uses a rear transaxle connected to the engine via a torque tube. If supplemental support is needed to prevent powertrain movement during mount removal, position an adjustable support stand under the torque tube or transaxle per the manufacturer's recommended support points, raising it only until it just contacts the component without applying lifting force. Verify the manufacturer's service procedure for the correct support location before proceeding. Note: Note: The DB9 uses a rear-mounted transaxle connected via a torque tube, so there is no transmission bellhousing directly behind the engine. Ensure the engine is adequately supported from above (Step 1) before removing the rear mount. If additional stabilization is desired, position an adjustable support stand under a structural point of the engine/torque-tube area, raising it only until it just contacts without applying lifting force. Verify the engine is stable before removing the rear mount.
4. 4

   Remove rear crossmember heat shields
   Locate the heat shield panels protecting the rear crossmember area. Remove the fasteners securing these shields (typically Torx T25 or T30 screws). Remove shields to expose the rear engine mount assembly and frame attachment points.
5. 5

   Remove engine mount through-bolt
   Locate the large horizontal through-bolt that passes through the center of the rear engine mount assembly, connecting the engine bracket to the mount bushing. Using a socket and breaker bar, remove the through-bolt nut, then drive or pull the through-bolt out. Confirm the through-bolt and nut size against OEM documentation; the bolt may require significant force to extract if corrosion is present. Note: Locate the through-bolt that passes through the rear engine mount assembly, connecting the engine bracket to the mount bushing (confirm mount design and bolt size against OEM documentation, as configurations vary). Using a socket and breaker bar, remove the through-bolt nut, then drive or pull the through-bolt out. The bolt may require significant force to extract if corrosion is present. Note: The through-bolt head/nut size and torque should be verified against OEM documentation; it may require significant force to extract if corrosion is present.
   Torque spec

   Engine Mount Through-Bolt119 Nm (88 lb-ft)
6. 6

   Remove engine-side mount bracket bolts
   Identify the bolts securing the upper mount bracket to the engine block/rear engine plate (bolt count to be verified against OEM documentation). These bolts thread into the engine block. Using appropriate socket, remove all bolts and retain for inspection. The bracket may remain temporarily attached to the mount. Note: Identify the bolts securing the upper mount bracket to the engine block at the rear of the engine (verify exact count against OEM documentation). These bolts thread into the engine block. Note: Identify the bolts securing the upper mount bracket to the engine block at the rear of the engine (verify exact count against OEM documentation). These bolts thread into the engine block flange — note there is no bellhousing at this location on the DB9's rear-transaxle layout. Using the appropriate socket, remove all bolts and retain for inspection. The bracket may remain temporarily attached to the mount.
   Torque spec

   Engine Mount-to-Block Bolts49 Nm (36 lb-ft)
7. 7

   Remove frame-side mount bolts
   Locate the bolts securing the lower mount assembly to the rear crossmember/subframe. Verify the exact number of bolts securing the mount assembly to the frame brackets against OEM documentation before removal. Remove these bolts completely. Note the position and orientation of any spacers or alignment shims present. Note: Locate the bolts securing the lower mount assembly to the subframe/frame brackets (verify exact count and arrangement against OEM documentation). Remove these bolts completely. Note the position and orientation of any spacers or alignment shims present.
   Torque spec

   Engine Mount-to-Frame Bolts82 Nm (61 lb-ft)
8. 8

   Lower engine slightly and extract mount assembly
   Using the engine support equipment, carefully lower the rear of the engine approximately 1-2 inches. Monitor clearance around the engine bay to ensure no contact with firewall, brake lines, or wiring harnesses. Once the engine is lowered, the rear mount assembly should be free to maneuver out from between the engine bracket and frame mounting points. Extract the mount assembly, noting the orientation of all components.
9. 9

   Inspect mounting surfaces and hardware
   Thoroughly inspect the engine-side mounting flange and frame brackets for cracks, elongated bolt holes, or distortion. Examine all removed bolts for thread damage or stretching. Clean all mounting surfaces with a wire brush, removing rust, old thread locker, and debris. Apply penetrating oil to the frame bracket bolt holes and allow to drain.
10. 10

    Position new rear mount assembly
    Position the new rear engine mount assembly between the engine mounting flange and frame brackets. Ensure the mount orientation matches the original configuration, with any alignment marks or offset features correctly positioned. The mount may need to be angled to fit into position while the engine is lowered.
11. 11

    Install and hand-tighten frame-side bolts
    Install all frame-side mount bolts with any spacers or shims in their original positions. Thread bolts in by hand to ensure proper thread engagement. Hand-tighten all bolts but do not torque yet. Verify the mount sits flush against the frame brackets on both sides.
12. 12

    Raise engine to working height
    Using the engine support equipment, slowly raise the rear of the engine until the engine-side mounting flange aligns with the upper bracket on the mount assembly. Monitor engine position and ensure even lifting without binding. Stop when the mounting holes align.
13. 13

    Install engine-side bracket bolts
    Install the bolts (verify exact count against OEM documentation) securing the mount bracket to the engine block/rear engine plate flange — note there is no bellhousing at this location on the DB9's rear-transaxle layout. Thread bolts in by hand to verify proper alignment, then hand-tighten. Ensure the bracket sits flush against the engine mounting surface before proceeding. Thread bolts in by hand to verify proper alignment, then hand-tighten. Ensure the bracket sits flush against the engine mounting surface before proceeding.
    Torque spec

    Engine Mount-to-Block Bolts49 Nm (36 lb-ft)
14. 14

    Install engine mount through-bolt
    Insert the through-bolt through the engine bracket and mount bushing assembly. Install the through-bolt nut and hand-tighten. Verify the bolt passes freely through all components without binding, indicating proper alignment.
    Torque spec

    Engine Mount Through-Bolt119 Nm (88 lb-ft)
15. 15

    Torque all mount fasteners in sequence
    Torque fasteners in the following sequence: First, torque the engine-side bracket bolts in a cross pattern to OEM-specified torque. Second, torque all frame-side mount bolts to OEM-specified torque, alternating between left and right sides. Finally, torque the through-bolt nut to OEM-specified torque. Confirm all values against Aston Martin service documentation, as database sources conflict on the frame-side spec. Verify all fasteners are tight. Note: Torque fasteners in the following sequence using OEM-verified specifications: First, torque the engine-side bracket bolts in a cross pattern to the manufacturer-specified value. Second, torque the frame-side mount bolts alternating between sides to the manufacturer-specified value. Finally, torque the through-bolt nut to the manufacturer-specified value. Do NOT use generic torque figures — confirm each value against Aston Martin service documentation for the 2009 DB9. Verify all fasteners are tight. Note: Torque fasteners in the following sequence, using OEM-verified values: First, torque the engine-side bracket bolts in a cross pattern. Second, torque all frame-side mount bolts, alternating between left and right sides (note: exact frame-side torque value must be confirmed against Aston Martin service documentation — do not use generic or assumed figures). Finally, torque the through-bolt nut. All torque values must be verified against Aston Martin service documentation before final tightening.
    Torque spec

    Engine Mount-to-Block Bolts49 Nm (36 lb-ft)

    Engine Mount-to-Frame Bolts82 Nm (61 lb-ft)

    Engine Mount Through-Bolt119 Nm (88 lb-ft)
16. 16

    Remove engine and transmission support
    Carefully release tension on the engine support equipment and verify the engine settles properly onto the new mount without abnormal movement or noise. Remove the engine support bar or hoist. Lower and remove the transmission jack or support stand from underneath.
17. 17

    Reinstall heat shields and exhaust
    Reinstall the rear crossmember heat shields using the original Torx fasteners. Raise the rear exhaust sections into position and reconnect the flange connections with new gaskets if the originals are damaged. Torque exhaust flange bolts evenly in a cross pattern to the manufacturer-specified value from Aston Martin service documentation. Note: Torque exhaust flange bolts evenly in a cross pattern to the OEM-specified torque (confirm value against Aston Martin service documentation). Note: Torque exhaust flange bolts evenly in a cross pattern to the OEM-specified value (verify against Aston Martin service documentation).
18. 18

    Reinstall undertray and reconnect battery
    Reinstall all engine undertray panels using the original Torx fasteners. Lower the vehicle to the ground. Reconnect the negative battery cable and verify proper connection.

Reassembly

1. All fasteners must be torqued to specification in the sequence provided to ensure proper load distribution
2. Ensure no wiring harnesses, brake lines, or coolant hoses are pinched or in contact with the new mount
3. Exhaust flanges must be reconnected with proper gaskets to prevent exhaust leaks
4. Engine undertray panels must be fully secured to maintain proper aerodynamics and component protection

Verification

• Start the engine and observe the mount area for excessive movement or vibration
• With engine running, shift through all transmission gears (P-R-N-D) and verify smooth engagement without excessive engine movement
• Perform a short test drive and verify no new vibrations are present at idle, acceleration, or deceleration
• Re-inspect all mount bolts after test drive to ensure none have loosened
• Inspect exhaust connections for leaks (visual and audible check)
• Verify no contact between engine and chassis during normal operation

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