51 21 090 Removing and installing/replacing door lock in left or right front door

Necessary preliminary tasks 

• Remove FRONT DOOR WINDOW GLASS 

Release screws (1) on H-strut.

Tightening torque 51 21 13AZ .

Remove H-strut (2).

Release screw (3) with special tool 51 3 300.

Tightening torque 51 21 14AZ .

Release screw (4).

Tightening torque 51 21 14AZ .

Window rail (5) remains in door.

Fig 1: Removing Screw Using Special Tool (51 3 300)

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Unlock and disconnect plug connection (2) at tabs (1).

Disengage Bowden cable (3) from door lock (4).

Unclip lock knob control rod (5).

Fig 2: Identifying Plug Connection With Tabs, Bowden Cable, Door Lock And Control Rod

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Release screws (1).

Door crashpad (2) remains in door.

Fig 3: Identifying Door Crashpad With Screws

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Release screws (1).

Tightening torque 51 21 1AZ .

Remove door lock (2) from door (3).

Fig 4: Identifying Door With Lock And Screws

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Disengage Bowden cable (1) from door lock (2).

Fig 5: Identifying Bowden Cable With Door Lock

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Installation: 

Seal (1) on door lock (2) must not be damaged.

Fig 6: Identifying Seal On Door Lock

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Installation: 

• Install door lock and insert screws (1), do not tighten down.
• Slide special tool 51 2 190 into opened rotary striker until striker engages in first stage

Fig 7: Sliding Special Tool (51 2 190) Into Opened Rotary Striker

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Installation: 

• Pre-tension door lock (1) with knurled screw (2) until special tool 51 2 190 just contacts corner points (3)

Fig 8: Installing Door Lock Using Special Tool (51 2 190)

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Door lock seal must rest uniformly on inner door panel (water ingress).

• Tighten down door lock screws, tightening torque 51 21 1AZ .