BMW X3 Service & Repair Manual: Straightening aluminum components in structure

• Reshaping or heating extruded profiles and cast parts is not permitted! Failure to comply with this requirement would have the following results:
  In the case of reshaping, weld seams (E52) or bonded connections (E60, E61, E63, E64) tear in the surrounding area.

  In the case of reshaping, the material loses up to 40 % of its original strength.

  In the case of heating, the material loses up to 40 % of its original strength.

  The adhesive is destroyed at temperatures ≥120 ºC (E60, E61, E63, E64).

  Extruded profiles and cast parts which show visible or measurable signs of deformation must be replaced.

  Perform the check for deformation with the aid of the straightening system.

  For optical testing, strip adjoining components in cases of doubt.

  Extruded profiles are used in the E52 as engine supports, door posts, side members, etc.

  Extruded profiles are used in the E60, E61, E63, E64 as engine supports.

  Cast parts are used in the E60, E61, E63, E64, E70, E71 as spring supports.

• Reshaping of extruded profiles and cast parts may only be used to achieve optimum joining of connection faces (e.g. when bulkhead is damaged). Reshaped parts must be replaced.

  Repairs which affect the attachment points of mechanical assemblies and chassis/suspension components must be carried out on the straightening bench. Use the vehicle-specific set of attachments set or vehicle- specific data sheet.

  Straightening attachment supports and data sheets are also available for the top section, e.g.: door posts, soft top mounts, cowl panel, tailgate hinges, etc.

• Check windscreen and rear window apertures for curvature by inserting the original glass.
• Take the gap dimensions for doors, engine compartment lid and tailgate from the vehicle-specific gap dimension diagram.
• Exceptions on the E60, E61, E63, E64:
  Carrier support and bulkhead may be straightened if they do not have any cracks, sharp-edged damage or holes. After repair work, check parts again for cracks.

  Examine adjoining adhesive flanges for peeling off. If necessary, seal and preserve with SEALANT.

  Observe the frame reference dimension for the carrier support.

  Any repairs to the bulkhead if cracked outside the approved scope of repair work are only permitted after consultation with and approval by BMW.