Front Door Latch: Service and Repair

51 21 090 Removing And Installing/Replacing Door Lock On Left Or Right Front Door







Necessary preliminary work:
- Completely close side window if necessary
- Partially remove sound insulation (in area of door lock/rear guide rail, power window regulator)







Disconnect Bowden cable at bottom (1) and then from top (3) at door lock (2).

Installation note:
Bowden cable must be correctly engaged in fixture at bottom (1) and top (3) of door lock (2).







Loosen nuts at rear guide rail (1) of power window, release the lower nut (3).

Tightening torque 51 33 1AZ.

Feed out rear guide rail (1) toward the bottom so that the guide rail can swing toward the door middle.







Unclip locking rod (1).

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

Release screws (3) on door lock.

Feed out door lock (4) between inner door panel and rear guide rail.







Installation note:
Only for door with lock barrel:
- Feed in paddle (1) of lock barrel correctly back into the door lock.







Installation note:
- 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







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

IMPORTANT:
- To tension door lock (1), it is only permitted to tighten knurled screw (2) by a further 1 to 1.5 turns (max.) (risk of damage).
- Door lock seal must rest uniformly on inner door panel (water ingress).

- Tighten screws of door lock Tightening torque 51 21 4AZ.