TRADE OF VEHICLE BODY REPAIR - eCollege

Module 3– Unit 1
Twist Damage
Twist damage usually occurs to independent frames. The material is
so hard the chassis does not mash on impact but bends up or down.
This bending usually causes a deformation to the entire chassis
resulting in a twisting effect. It is difficult to repair this damage as
visibility and access is restricted. Some times it is necessary to
remove the body from the chassis but this is time consuming and
on a practical level usually results in the vehicle creaking after with
obvious customer complaints.
Diamond Damage
When a separate (independent) chassis is struck off set, it is possible
that the chassis may not bend at all. The complete side member will
move back, this means that cross members that were at 90º are out
of alignment creating a diamond effect between cross members.
Repairs to this will need a pull on the damaged chassis and a
counter pull on the other. Standard 10 ton pulling equipment may
not be strong enough.
Remember:
Figure 26: Diamond Damage
Never heat this or any chassis during repair. Heating the steel above
723ºC will dramatically affect the grain structure of the steel, which
means the characteristics of the steel will be changed. Even heating
alloy steel above 200ºC may change the steel depending on its
alloying elements.
Vehicle Body Repairs - Phase 2 34