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Home >> BMW >> 2013 >> 740Lxi >> Repair and Diagnosis >> External Pages >> Different car >> Section 472 (Exhaust System - Repair) >> Mufflers >> 18 12 050 Replacing center muffler (N63)

18 12 050 Replacing center muffler (N63)

WARNING: This page is about a different car, the 2011 BMW 750xi, 2011 BMW 750Lxi, 2010 BMW 750xi, and 2010 BMW 750Lxi. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required 

WARNING: Scalding hazard! 
Only perform these tasks after exhaust system has cooled down.

Support center silencer with special tool 31 2 220 and a suitable universal lifter.

Fig 1: Support Exhaust System With Special Tool (31 2 220)
G04742070Courtesy of BMW OF NORTH AMERICA, INC.

Release screws (1).

Tightening torque 18 20 6AZ .

Only when independent heating is fitted: release screw (2) on metering pump.

Tightening torque 18 20 7AZ .

Release screws (3) on underbody panels.

Remove reinforcement plate (4).

Fig 2: Identifying Screw On Metering Pump, Screw On Underbody Panels And Reinforcement Plate
G06889336Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: If the cutting line is not marked by a punch mark in the pipe, determine the cutting line by means of the pipe length on the new center muffler.

Carry over cutting line to faulty center muffler and mark.

Secure center muffler against falling off.


Cut through exhaust pipes at marked point with a suitable tool.
Fig 3: Identifying Cutting Line On Centre Muffler
G06889343Courtesy of BMW OF NORTH AMERICA, INC.

Picture shows the left side, the procedure for the right side is identical.

Slacken nut (1).

Tightening torque 18 20 4AZ .

Fig 4: Identifying Exhaust System Nut
G06889337Courtesy of BMW OF NORTH AMERICA, INC.

Installation: 

Adjust center muffler to fit and connect with clamps.

Centre clamp and tighten down.

Tightening torque 18 31 4AZ .

The procedure is identical on both sides.

Fig 5: Identifying Centre Muffler With Clamps
G04794086Courtesy of BMW OF NORTH AMERICA, INC.
NOTE: Check exhaust system for leaks.