4
Chassis damage can usually be grouped into five
basic types of damage, described as SAG, SWAY,
KICK-UP, DIAMOND and TWIST,
Even though chassis are made in many ways
(such as ladder, offset, X-type etc.), collision
impact will distort the chassis, or parts of it,
regardless of construction.
I. SAG
When hit from the front or rear, the chassis can
sag like a hammock and then look like this:
3. KICK-UP
Quite often with direct front or rear end damage,
only a part of the chassis will kick-up like this:
HOW TO IDENTIFY THE TYPE OF THE DAMAGE
2. SWAY
Often when hit from the side, either in the middle
or at one end, the chassis may develop sway
looking like this:
Or like this:
Sway in Unitised Bodies doesn’t bend the entire
body. Instead only one part of the body will be
moved out of line.
Kick-up on Unitized Bodies is more like SAG. There
is generally only only one major bend in the floor
pan.
4. DIAMOND
Chassis’ built with two parallel side rails may get
pushed out of square when hit on one corner.
Then they become diamond shaped and look
like this:
Hour glass, Unitised, or X-type chassis seldom “go
diamond”
5. TWIST
Sometimes the chassis will twist when the car goes
into a ditch, over a curb, etc., and will took like
this:
Top View of Sway
Top View of Sway
Side view of sag
These are the five classifications of chassis
damage. But remember, you will often find two
or more in the same job such as SAG and KICK-
UP. In some cases with front end damage the front
cross member or engine mounting will roll under
in addition to other types of chassis damage.
NOW that we know the types of chassis damage,
how do you determine if the chassis is bent? First,
if the car looks as if it has had a hefty jolt, get
underneath and LOOK AT THE CHASSIS. Are there
any places where the metal is torn? Are there
any places where the metals wrinkled? Does the
chassis look out of shape or bent? lf the answer
to ANY or ALL of these questions is yes, the
chances are that the chassis is bent.
Side view of twist
Side View of Kick-up
Top view of Diamond
