67 31 540 Removing and installing/replacing drive unit for head restraint adjustment (comfort seat)

Necessary preliminary tasks: 

• Remove both rear panels on front seat backrest  , see 52 14 198 REMOVING AND INSTALLING OR REPLACING REAR PANEL ON LEFT OR RIGHT FRONT SEAT BACKREST .

Disconnect plug connection (1).

Release screw (2).

Tightening torque 67 31 4AZ  , see 67 31 DRIVE, SEAT ADJUSTMENT .

Pull shaft (1) in direction of arrow out of shaft receptacle (2).

Installation: 

Make sure shaft (1) is correctly seated in receptacle (2).

Release retaining ring (3).

Feed out drive unit for backrest head adjustment (4) and remove.

Removal and installation only: 

Do not turn spindle (1) in order not to change measurement A.

Replacement: 

Adopt measurement A of removed drive unit for backrest head adjustment (2). If necessary, adjust measurement A by turning spindle (1).

Initialize  drive unit for backrest head adjustment, see 67 31... Notes on initializing electric seat servodrives .