Chassis Repair

Corrosion is the main factor affecting the useful life of any DS and there are a number of areas where it is particularly prone. These include the main sills, outer sills, jacking points, C pillar base, boot floor, rear cross member, rear bumper mounts and roof cant rail.

As an example; the main sills, which are the primary structural components of the chassis, are corrosion prone due to a design flaw. On the underside, strengthening panels spot welded to the floor pan and running the length of the sills add strength to the box section. These panels have a 45° fold in them which matches the sill / floor pan profile, but where the floor pan has indents or scallops every 100mm or so at the fold line (to add stiffness) the strengthening panels do not and also do not fully cover these scallops above the fold line thereby creating a perfect rust trap.

rotten sill thumb

Resolution of this problem involves replacement of the corroded metal and seam welding the replacement strengthening panel rather than spot welding,  preventing re-occurrences.

Here is a corroded sill having been cleaned up with all paint and underseal removed. The strengthening panel is removed in the next picture to show the scallops in the floor panel. In this case the floor is not holed and a new strengthening panel can be attached.


chassis sill scallops thumb