BMW X3 Service & Repair Manual: Straightening aluminum component on the outer skin

1.0 Prerequisites

The component must be replaced if there are cracks and it is neither possible to drill into the end of the crack, nor to weld it.

2.0 Recommended tools

• Only use tools specifically designed for aluminum repairs.
• Do not use tools and operating fluids that have already been used for steel repairs (e. g. grinding wheel). Danger of contact corrosion.
• Do not use any sharp-edged tools (notch effect).

3.0 Straightening outer skin

• "Cold" straightening: Press dents out from their center and smooth in an outwards direction with gentle taps.

  In the case of small, soft dents (hail and parking damage), this is also possible without damaging the paintwork. Special tools and a trained employee are needed.

• "Hot" straightening: Heat the component in the damaged area with a hot air blower to approx. 60 Â ºC. This significantly reduces the force that needs to be applied for straightening.
• Avoid notching and cracking.
• Avoid hardening and overstretching.
• Avoid heating and excess temperature the outer skin over large areas.