18 12 046 Replacing front silencer (N52T)

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Special tools required:

31 2 220

WARNING: Risk of burning!
Only perform this repair work after engine has cooled down.
Danger of injury!
Removal of the exhaust system must be carried out with the assistance of a second person.

Support front silencer with special tool 31 2 220 or a suitable jack and protect from falling down.

Fig 1: Supporting Front Silencer Using Special Tool (31 2 220)

Courtesy of BMW OF NORTH AMERICA, INC.

European version only:

NOTE: If the separation point is not marked by a punch mark in the pipe, determine the separation point by means of the pipe length on the new front silencer.
Carry over separation point to faulty front silencer and mark.
Secure front silencer against falling out.
Cut through exhaust pipes at marked point with a suitable tool.

Fig 2: Identifying Silencer Separation Point

Courtesy of BMW OF NORTH AMERICA, INC.

US version only

NOTE: If the separation point is not marked by a punch mark in the pipe, determine the separation point by means of the pipe length on the new front silencer.
Carry over separation point to faulty front silencer and mark.
Protect the front silencer and primary catalytic converter, left (1) and right (2) against falling down.
Cut through exhaust pipes at marked point with a suitable tool.

Fig 3: Identifying Silencer Separation Point

Courtesy of BMW OF NORTH AMERICA, INC.

Unscrew nuts.

Installation note:

Replace self-locking nuts.

Replace gasket.

Tightening torque: 18 31 1AZ .

Fig 4: Locating Self-Locking Nuts

Courtesy of BMW OF NORTH AMERICA, INC.

Slacken nut (1).

Tightening torque: 18 31 3AZ .

Lower and remove front silencer carefully with assistance of a second person.

Fig 5: Identifying Silencer Nut

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Fit front silencer and connect with clamp.

Center clamp and tighten down.

Tightening torque: 18 31 4AZ .

US version only

Fit front silencer and connect with clamp with primary catalytic converters and rear silencers.

Center clamp and tighten down.

Tightening torque: 18 31 4AZ .

Fig 6: Identifying Silencer Clamp

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Check rubber mount for damage.

If necessary, replace damaged rubber mounts.

Check exhaust system for leak tightness.