52 14 899 Additional work (normal/ electric) with defective drive for longitudinal adjustment

Set seat tilt adjustment to max. up setting.

Release screw (1) on actuator drive (2) of longitudinal seat adjustment.

Fig 1: Identifying Screw On Actuator Drive

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Release screw (1) on servodrive (2) of longitudinal seat adjustment and remove servodrive (2).

Activate the operating switch for the seat position adjustment:

1. No function:
   • Disconnect plug for longitudinal seat adjustment
   • Connect new servodrive and check function
   • If servodrive is running, gear is O.K.
   • Reassemble front seat
     Fig 2: Identifying Servodrive

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2. Actuator drive running:
   • Transmission for longitudinal seat adjustment defective!
   • Continue with

     Disassembly of faulty gear for longitudinal seat adjustment

Disassembly of faulty gear (1) for longitudinal seat adjustment: 

1. (2) Input shaft
2. (3) Internal gear
   Fig 3: Identifying Input Shaft And Internal Gear

   Courtesy of BMW OF NORTH AMERICA, INC.

Using a pneumatic saw (1), cut through drive shaft (2) from rear.

Fig 4: Identifying Pneumatic Saw

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Remove drive shaft (1) from gear (2).

Fig 5: Removing Drive Shaft From Gear

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Release screw (1) and remove gear (2).

Fig 6: Removing Screw And Gear

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Over rest of drive shaft (1), adjust front seat,

release screws on floor panel

and remove front seat.

Fig 7: Identifying Drive Shaft

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Replace seat mechanism on front seat.