Replacing center silencer

Preliminary work 

• Refer to REMOVING THE UNDERBODY PLANKING OF THE TRANSMISSION ON THE SIDE .
• Refer to REMOVING THE CONNECTING SUPPORT FROM THE TUNNEL .
• Refer to REMOVING THE TORSION STRUT ON THE REAR LEFT AND RIGHT .
• Refer to IF INSTALLED: REMOVING THE REAR AXLE COVER .
• Refer to REMOVING THE REAR DIFFUSER .

Replacing center silencer 

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• If the Separation point (1) is not marked by a grain (2) in the pipe, then determine the separation point (1) by means of the length of the pipe on the new rear silencer.
• Apply the separation point (1) to faulty rear silencer and mark it.
• Protect the front silencer from falling.
• Cut through exhaust pipes at the marked point with a suitable tool.

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• Use a suitable jack to secure the exhaust system (1) from falling down. If the exhaust system is drained while under tension, there is the risk that the retaining bolts (2) will break.

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• If the separation point (1) is not marked by a punch mark (2) in the pipe, then determine the separation point (1) by means of the pipe length on the new center muffler.
• Apply the separation point (1) to faulty center silencer and mark it.
• Secure center silencer against falling off.
• Cut through exhaust pipes at the marked point with a suitable tool.

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• Loosen screw (1).
• Lower the exhaust system holder (2).

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• Loosen screw (1).
• Lay ground strap to one side.
• Loosen screw (3).
• Lower the exhaust system holder (2).
• Remove the center silencer.

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• Remove the rubber mount (2) from the bars (1) of the former rear silencer.
• Install the rubber mount (2) on the bars (1) of the rear silencer.

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• Replace the circlips (2).

  Parts:  Clamps

• Slide circlips (2) onto the center silencer.
• Adjust the rear silencer (1) on the center silencer (3).

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• Replace the circlips (1).

  Parts:  Clamps

• Slide circlips (1) onto the center silencer (2).
• Adjust the left-hand front pipe (4) and the right-hand front pipe (3) on the center silencer (2).

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• Position the holder of the exhaust system (2).
• Position the ground strap.
• Tighten down screw (1).
  TIGHTENING TORQUES SPECIFICATION
  
  

  Exhaust system to rear axle carrier
  M8x25 Replace screw.	tightening torque	28 Nm

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• Tighten down screw (3).
  TIGHTENING TORQUES SPECIFICATION
  
  

  Exhaust system to rear axle carrier
  M8x25 Replace screw.	tightening torque	28 Nm

• Position the holder of the exhaust system (2).
• Tighten down screw (1).
  TIGHTENING TORQUES SPECIFICATION
  
  

  Exhaust system to rear axle carrier
  M8x25 Replace screw.	tightening torque	28 Nm

  Courtesy of BMW OF NORTH AMERICA, INC.

• The openings of the circlips (1) must point outwards.
• Tighten nuts in area (2) of the circlips (1).
  TIGHTENING TORQUES SPECIFICATION
  
  

  cl  .
  Nuts	Tightening torque	45 Nm

  Courtesy of BMW OF NORTH AMERICA, INC.

• The openings of the circlips (2) must point outwards.
• Tighten nuts in area (1) of the circlips (2).
  TIGHTENING TORQUES SPECIFICATION
  
  

  cl  .
  Nuts	Tightening torque	45 Nm

  Courtesy of BMW OF NORTH AMERICA, INC.

Follow-up work 

• Refer to INSTALLING THE REAR DIFFUSER .
• Refer to IF INSTALLED: INSTALLING THE REAR AXLE COVER .
• Refer to INSTALLING THE TORSION STRUT ON THE REAR LEFT AND RIGHT .
• Refer to INSTALLING THE CONNECTING SUPPORTS ON THE TUNNEL .
• Refer to INSTALLING THE UNDERBODY PLANKING OF THE TRANSMISSION ON THE SIDE .