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

1. Remove sound insulation on front door. Refer to 51 48 ... REMOVING AND INSTALLING/REPLACING SOUND INSULATION IN FRONT DOOR, LEFT OR RIGHT .
2. Driver's side only:
3. Remove complete lock cylinder. Refer to 51 21 140 REMOVING AND INSTALLING/REPLACING COMPLETE LOCK CYLINDER .

Disconnect plug connection (1) on door lock (2).

Fig 1: Disconnecting Plug Connection On Door Lock

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Unclip ball head (1).

Fig 2: Detaching Bowden Cable From Support On Door Lock

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Detach Bowden cable (2) from support (3) on door lock.

Release screws (1).

Remove door lock (2) with linkage (3).

Fig 3: Removing Door Lock With Linkage

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Installation: 

Insert linkage for locking knob through opening in inner door plate.

Do not bend linkage (3).

Replace screws (1).

Tightening torque 51 21 1AZ. Refer to BODY EQUIPMENT - TIGHTENING TORQUES .

Installation: 

Carry out function check only with door open.

Fig 4: Identifying Latch Lock

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• Close rotary latch lock (1) with a screwdriver,
• lock car with car key,
• unlock car with car key,
• open rotary latch lock (1) with outside door handle,
• if rotary latch lock (1) opens, then O.K.
• if rotary latch lock (1) fails to open
• a new lock actuator must be fitted.

Only replacement:

Lift out lock (1) and detach Bowden cable (2) from fixture (3).

Fig 5: Removing Bowden Cable Nipple From Lever

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Remove Bowden cable nipple (4) from lever (5).

Only replacement:

Unclip linkage for locking knob (2) from support (1) and feed out of guide (3).

Fig 6: Identifying Linkage For Locking Knob

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Installation: 

Following parts must not be damaged or missing:

1. Spring
2. Mount for Bowden cable of inside door handle
3. Mount for linkage of locking knob
4. Mount for paddle of lock barrel (driver's side only)

The illustration shows the left driver's door lock.

Fig 7: Identifying Left Driver's Door Lock

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