Transmission Mount

Remove and replace the transmission mount on a 2007-2013 Mercedes-Benz S65 AMG with M275 6.0L V12 BiTurbo engine to eliminate vibration and improve driveline stability.

Warnings

Tools required

Parts

• Transmission mount (M275 engine specific) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine and transmission to cool completely (minimum 1 hour after operation)
3. Raise vehicle using appropriate lift points and support securely on jack stands
4. Remove engine undertray panels for access to transmission mount area
5. Inspect transmission mount condition and surrounding area for any fluid leaks or damage
6. Position transmission jack or support under transmission pan with wood block to distribute load

Procedure

1. 1

   Support transmission weight
   Position transmission jack under transmission oil pan with a wooden block to protect pan surface. Raise jack until it just contacts transmission but does not lift it. The goal is to support weight without creating upward pressure. Verify transmission is stable and cannot shift during mount removal.
2. 2

   Remove heat shield or covers if present
   Locate and remove any heat shields, protective covers, or plastic covers around transmission mount area. These are typically secured with 10mm bolts. Set aside hardware for reinstallation.
3. 3

   Disconnect transmission mount upper fasteners
   Locate the transmission mount upper bolts connecting mount to transmission. On the M275 application, these are typically 17mm fasteners. Remove upper transmission mount bolts connecting rubber mount to transmission bracket. Support mount while removing final bolt to prevent it from falling.
   ⚠Transmission may settle slightly when upper bolts are removed. Ensure jack is properly positioned.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)
4. 4

   Remove crossmember-to-chassis fasteners
   Locate the crossmember bolts that secure the transmission crossmember to the chassis rails. These are typically on both sides of the crossmember. Remove these bolts while ensuring transmission jack maintains support. On S65 AMG models, there may be multiple bolt sizes used in crossmember attachment.
   Torque spec

   Crossmember Bolts95 Nm (70 lb-ft)
5. 5

   Lower crossmember assembly
   With all crossmember fasteners removed, carefully lower the transmission jack slightly to create clearance. The crossmember and mount assembly should lower together. Lower only enough to access mount-to-crossmember fasteners (approximately 2-3 inches). Do not allow transmission to hang on driveshaft or shift linkage.
   ⚠Monitor exhaust system clearance and shift linkage during lowering. Stop if any binding occurs.
6. 6

   Remove mount from crossmember
   With crossmember lowered, access the mounting bolts that secure the transmission mount to the crossmember. These fasteners attach the rubber mount to the steel crossmember bracket. Remove these bolts and extract the old transmission mount. Inspect crossmember and mounting surfaces for damage or corrosion.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)

   Mounting Bolts82 Nm (61 lb-ft)
7. 7

   Install new transmission mount
   Position new transmission mount onto crossmember in same orientation as original. Verify mounting studs or bolt holes align properly. Install mounting bolts finger-tight initially. Ensure mount rubber is not twisted or pinched. Verify mount orientation matches original installation with any offset or angle positioned correctly for this application.
8. 8

   Torque mount-to-crossmember fasteners
   Tighten the mount-to-crossmember bolts to specification. Tighten in a cross pattern if multiple bolts are present to ensure even seating of mount. Do not fully torque crossmember-to-chassis bolts yet.
   Torque spec

   Transmission Mount Bolts65 Nm (48 lb-ft)

   Mounting Bolts82 Nm (61 lb-ft)
9. 9

   Raise and align crossmember
   Using transmission jack, carefully raise crossmember and transmission assembly back to original position. Align crossmember bolt holes with chassis mounting points. You may need to use pry bar for minor adjustments. Install all crossmember-to-chassis bolts finger-tight first to ensure proper alignment before final torquing.
10. 10

    Torque crossmember and upper mount bolts
    Torque crossmember-to-chassis bolts to specification according to bolt size and location. Follow with upper transmission mount bolts connecting mount to transmission bracket. Torque all fasteners in proper sequence and to correct specification. Allow transmission weight to settle naturally onto mount before final torquing.
    Torque spec

    Crossmember Bolts95 Nm (70 lb-ft)

    Transmission Mount Bolts65 Nm (48 lb-ft)
11. 11

    Reinstall covers and shields
    Reinstall any heat shields, protective covers, or plastic covers removed during disassembly. Ensure all clips and fasteners are properly seated. Torque cover bolts to specification.
12. 12

    Remove transmission support and lower vehicle
    Carefully lower and remove transmission jack from under vehicle. Reinstall undertray panels and any other removed components. Lower vehicle from jack stands and perform final checks before test drive.

Reassembly

1. Verify all fasteners are torqued to specification before lowering vehicle
2. Ensure no tools or parts are left in engine bay or under vehicle
3. All heat shields and covers must be reinstalled to prevent heat damage
4. Double-check that transmission jack has been fully removed before lowering vehicle

Verification

• Start engine and verify no unusual vibrations at idle in Park and Drive with brake applied
• Perform test drive including smooth acceleration, deceleration, and upshifts through all gears
• Listen for any clunking or excessive movement during throttle application and release
• Verify no vibration at idle or under load that would indicate improper mount installation
• Inspect mount installation from underneath after test drive to confirm no fastener loosening or mount movement
• Check for any fluid leaks around transmission area that may have been disturbed during service

Related trouble codes on this vehicle

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