Collision diagnosis

I - UNDERBODY CHECK

Before starting body repair on a vehicle, even one that appears only slightly damaged, carry out the following checks:

VISUAL CHECK

This check consists of examining the underbody around the mechanical mountings and in the crumple or vulnerable zones in order to detect the presence of deformation creases.

GAUGE CHECK

The visual check may be supplemented by a gauge check, which allows certain deformations to be measured by symmetrical comparison (for more detail on each point to be checked, refer to the repair bench section below).

GAUGE CHECK

This is the only check that determines whether the impact has or has not affected the vehicle's road behaviour.

IMPORTANT: In borderline cases, do not neglect to check the running gear components, which may also have been deformed.

As a rule, no welded body structure component should be replaced without first making sure the underbody has not been affected by the impact.

Chronological order of checks:

FRONT impact:
1: B3 - G' = B3' - G
2: G' - C = G - C'
3: G' - H = 1391 mm
4: G - H' = 1401 mm

REAR impact
1: G - B3' = G' - B3
2: G - B1' = G' - B1

CAUTION: The front and rear reference points are not symmetrical. To check them, measure the centre distance between these points.

H, H' = 968 mm
J1, J1' = 1102 mm
G' - H = 1391 mm
G - H' = 1401 mm

REMINDER

The underbody holes are fitted with plastic plugs to seal the hollow sections.

When using the pinch-weld clamp, some of these plugs must be removed.

If any of them is damaged, it must be replaced with a new one to maintain the vehicle's anti-corrosion warranty.

GAUGING POINTS

Point G Starting reference for checking points (B3) and (H).

Point H Front side member locating pin.

NOTE: Partial removal of the plastic protection is required to access point (H).

Point B3 Body locating pin.

Point J1 Rear end of rear side member.

POINTS H, H'

Front side member locating pin.

POINTS J1, J1'