52 14... Additional work in event of faulty drive/gearing for longitudinal adjustment

Necessary preliminary work: 

• Remove FRONT DOOR SILL COVER STRIP

Release screw (1).

Tightening torque 72 11 01AZ .

Remove inertia reel unit (2).

Installation note: 

The inertia reel (2) is coded to prevent incorrect assembly.

Make sure metal clamp is securely seated.

Fig 1: Identifying Inertia Reel Unit And Screw

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Fold back carpet (1) to access the screws.

Fig 2: Folding Back Carpet To Access Screws

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Release screws (1).

Tightening torque 52 10 06AZ .

Fold upper seat section (2) backwards in direction of arrow.

Fig 3: Folding Upper Seat Section Backwards

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Unfasten plug connection (1) and disconnect.

Undo rivet connections (2).

Completely remove rivet residue.

Fig 4: Identifying Plug Connection And Rivet Connections

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Lift drive (1) with flex shaft out of guide in direction of arrow.

Pull flex shaft on left and right out of gearbox.

Fig 5: Lifting Drive With Flex Shaft Out Of Guide

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Installation note: 

Slide seat rail with opening forwards or backwards until bushing for flex shaft mounting (4) of worm gear is flush.

Slide in short flex shaft (1).

Insert drive (2) and slide in flex shaft (1) into square on drive (2).

Bend long flex shaft (3) upwards and insert into bushing for flex shaft mounting (4) of worm gear.

Fig 6: Identifying Flex Shafts, Drive, And Flex Shaft Mounting

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Installation note: 

PTFE hoses (1) are shrink-fitted onto end pieces.

Check hoses (1) for damage.

Fig 7: Identifying PTFE Hoses Shrink-Fitted Onto End Pieces

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Installation note: 

• Ensure flex shaft in drive and worm gear is properly installed
• Carry out FUNCTION CHECK WITH ADAPTER CABLE 

Replacement: 

INITIALIZE backrest adjustment motor.

Fig 8: Identifying Backrest Adjustment Motor

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Release screws (1) at front.

Fig 9: Identifying Screws At Front

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Installation note: 

Install new drive for longitudinal seat adjustment.

Move front seat forwards.

Release screws (1) at rear.

Lift out front seat and assemble.

Fig 10: Identifying Screws At Rear

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Installation note: 

• Make sure flex shaft is correctly fitted on drive
• Carpet must not get between seat rails and floor panel in area of attachment points (groaning noises)
• Powerlok screws must be replaced and must not  be reused
• Powerlok screws are mechanical screw locks with trilobular threads
• Insert all screws loose to avoid twisting
• Tighten down all screws to specified torque

  Tightening torque 52 10 1AZ .