52 10 899 Additional work (normal/electric) in event of faulty drive for longitudinal adjustment (Z3 Roadster, M Roadster, Z3 Coupe, M Coupe)

Move seat tilt adjustment upwards.

Unfasten screws on actuator drive (1) for longitudinal seat adjustment and remove actuator drive.

Fig 1: Locating Screws Actuator Drive

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Pull input shafts (2) out of left/right transmissions.

Activate the operating switch for the seat position adjustment:

1. No function:

   Disconnect plug connection (1) and connect new actuator drive.

   Check function, if O.K. install actuator drive (transmission O.K.)

2. Actuator drive running:

   Transmission for longitudinal seat adjustment defective!

   Fig 2: Disconnecting Plug Connection

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Only with defective transmissions:

Insert input shaft (1) at one end into gear (2),

engage actuator drive (3) and thus locate faulty gear(s).

Fig 3: Inserting Input Shaft

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Disconnect plug connection of longitudinal seat adjustment and remove actuator drive (3) from car.

Remove the defective gear unit (2) with hammer and cold chisel (1):

Place cold chisel (1) between gear (2) and upper seat runner (3),

first place at one end and lever out gear (2).

Fig 4: Removing Defective Gear Unit

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Then lever out other end of gear (2) until it detaches itself from seat runner (3).

If necessary, remove second gear in this manner.

• Remove gear cables from guide screws.
• Insert screwdriver into end of guide screw.

  Twist guide screws alternately on both sides until the screws and nuts on both sides can be removed.

• Remove front seat and adjuster from car.
• Adjustment mechanism must be replaced.