LEMON Manuals: Even more car manuals for everyone
Home >> BMW >> 1998 >> 750iL >> Repair and Diagnosis >> Body & Frame >> Seats >> Seats - Repair Instructions >> Front seat normal electric >> 52 14 899 Additional work (normal/ electric) with defective drive for longitudinal adjustment

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

Move backrest forward to maximum extent.

Move front seat back/upwards until screws (1) are accessible.

Release screws (1) on front seat (2).

Installation: 

  1. Replace screws (microencapsulation).
  2. Tightening Torque. Refer to SEATS - TIGHTENING TORQUES .
  3. Fig 1: Releasing Screws On Front Seat
    G03215028

Raise front seat (1)

until support (2) is free of sleeve (3) on left/right.

Do not move front seat completely backwards (cable).

Fig 2: Raising Front Seat
G03215029

Raise front seat a little.

Feed cable (1) for belt tensioner (2) out of support (3).

Disconnect plug connection from servo drive for longitudinal seat adjustment.

Fig 3: Feeding Cable For Belt Tensioner Out Of Support
G03215030

Tilt front seat (electric) back so that it does not yet touch rear seat bench.

Release screws (1) from servo drive (2) for longitudinal seat adjustment and detach servo drive (2).

Disconnect plug connection (3) to servo drive for longitudinal seat adjustment.

Activate the operating switch for the seat position adjustment:

  1. No function:
    • Disconnect plug connection (3).
    • Connect new servo drive (2)
    • Check function
    • If servo drive is running, gear is OK.
      Fig 4: Releasing Screws From Servo Drive For Longitudinal Seat Adjustment
      G03215031
    • Reassemble front seat
  2. Actuator drive running:
  3. Transmission for longitudinal seat adjustment defective!
  4. Continue with

Disassembly of faulty gear for longitudinal seat adjustment

Disassembly of faulty gear for longitudinal seat adjustment: 

Cut through drive shaft (1) with a large bolt cutter or pneumatic saw.

Fig 5: Cutting Through Drive Shaft With A Large Bolt Cutter Or Pneumatic Saw
G03215032

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

Release nuts (3) and detach gear (2).

If necessary, remove gear on other side of seat runner.

The front seat can now be moved.

Fig 6: Removing Drive Shaft From Gear
G03215033

Remove inside panel from seat rail.

If necessary, detach hose from lumbar support pump.

Screw seat runners at front to seat frame for removal only.

Release screws from floor panel and remove front seat.

Replace both seat runners, refer to 52 17 010 REMOVING AND INSTALLING OR REPLACING BOTH SEAT RAILS ON LEFT OR RIGHT FRONT SEAT (COMFORT)  .