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: Releasing Screw On Actuator Drive

Courtesy of BMW OF NORTH AMERICA, INC.

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

Fig 2: Removing Servo Drive

Courtesy of BMW OF NORTH AMERICA, INC.

Activate the operating switch for the seat position adjustment:

1. No function:
   • Disconnect plug for longitudinal seat adjustment
   • Connect new servo drive and check function
   • If servo drive is running, gear is O.K.
   • Reassemble front seat
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: 

Fig 3: Locating Input Shaft & Internal Gear

Courtesy of BMW OF NORTH AMERICA, INC.

(2) Input shaft

(3) Internal gear

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

Fig 4: Cutting Through Drive Shaft

Courtesy of BMW OF NORTH AMERICA, INC.

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

Fig 5: Removing Drive Shaft From Gear

Courtesy of BMW OF NORTH AMERICA, INC.

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

Fig 6: Releasing Screw

Courtesy of BMW OF NORTH AMERICA, INC.

Over rest of drive shaft (1), adjust front seat, release screws on floor panel and remove front seat.

Fig 7: Removing Front Seat

Courtesy of BMW OF NORTH AMERICA, INC.