179 Chapter 9 Nonstructural Panel Repair
Copyright Goodheart-Willcox Co., Inc.
To remove the headliner, remove the roof trim first.
The roof trim consists of plastic panels that cover the
A, B, and C pillars and outline the door openings. The
trim may be held in place by screws, clips, Velcro,
or a combination of these items. Begin by locating
any screws holding the trim in place. In some cases,
covers are placed over the screw heads to help
conceal them. Remove any screws that are found. If
no screw heads are present, pull on an edge of the
plastic panel with your fingers and try to look under
it. Do not use a screwdriver or other pry tool when
removing the trim. Prying on the plastic panel with a
tool may distort the plastic and leave a stretch mark.
A stretch mark is a visible white band in the plastic
panel. If you can see clips under the panel, pull the
panel off by hand.
With the roof trim off, the headliner can be
accessed. Carefully detach the headliner from the roof.
The headliner may be attached to the roof with Velcro.
Most headliners have a semirigid backing. Folding this
backing will permanently crease the headliner. The
left and right edges of headliner may be able to be
rolled together slightly and removed from a hatchback
vehicle. In regular-cab pickup trucks, the headliner can
be taken out through a door. In other vehicles, the back
glass or windshield may need to be removed. If the
headliner cannot be easily removed, drop it down on
the seats and leave it inside the vehicle while the roof
is being repaired.
Roughing Out
The panel repair process can be divided into
two steps: roughing out and finishing. Roughing out
restores the damaged panel to its approximate contour,
and finishing completes the repair by restoring the
exact contour of the panel. Several operations may be
involved in the roughing out phase, including pulling,
pushing, stretching, leveling, raising, edge alignment,
and shrinking, as well as picking and filing.
Pulling
Longitudinal force can shorten a panel’s overall
length. A pulling operation can be used to lengthen the
panel. Pulling will remove folds, restoring the panel’s
overall length. If a corrective force is applied at the
point of impact, folds from longitudinal force can be
removed as the panel is lengthened. See Figure 9-12.
Lateral force can also shorten a panel by drawing
the edges inward. A pulling operation relies on the lift
reaction to restore panel dimension as the damage is
pulled out. The lift reaction means that as the panel
lengthens, the buckle unfolds, or straightens. A pull will
always try to form a straight line between the pull loca-
tion and the anchor location on the vehicle.
The lift reaction has the greatest effect when there
is a small angle between the attachment and the pull.
When the angle is large, the lift reaction has less
effect. See Figure 9-13.
To set up a pull, an attachment is needed. An
attachment, or hookup, connects the vehicle to the
pull. The quickest and simplest attachments are hooks.
See Figure 9-14. Hooks are placed on the back side
of the panel and a corrective force is applied to pull the
hook and the panel. The surface area of the correc-
tive force is the same size as the contact end of the
hook. If the metal where the contact end of the hook
is attached is weaker than the damage, the corrective
force will bend the contact area instead of pulling out
the damage. A large contact area is less likely to cause
damage and is preferred to a small contact area.
Bolts, washers, and nuts placed in existing holes
can also be used as attachments for pulling. The
vehicle shown in Figure 9-15 was hit in the rear corner
and has folding damage on the quarter panel. Length-
ening the panel will correct the damage. The attach-
ment is made by inserting an eyebolt through a hole
Goodheart-Willcox Publisher
Figure 9-13. A pulling operation relies on the lift
reaction to restore panel dimension as the damage is
pulled out. As the panel lengthens, the buckle unfolds.
A—A small angle gives a large lift reaction. B—A large
angle gives a small lift reaction.
Goodheart-Willcox Publisher
Figure 9-12. Folds can be removed from longitudinal
damage by exerting a corrective force that restores
panel length.
Pull
Pull
Anchor
Anchor
Small angle
A
B
Lift reaction
Large angle
Lift reaction
Anchor Corrective force
Point of impact