172 Section 2 Nonstructural Repairs
attachment area may be damaged if the folded area
resists movement. If the folds do not move, the metal
around the attachment holes may stretch or tear.
Another method of attachment is to weld a plate
onto the damaged area. A piece of scrap sheet metal
can be used, or specially made pull plates are available.
Figure 8-16 shows welded pull plates and a puller. The
plates are MIG welded to the damaged panel. Be careful
when welding, as excessive heat can further damage the
panel. The pull is concentrated at the welds. More welds
spread out the force of the pull. The pull can be made with
a slide hammer or a hydraulic ram. The pull must always be
parallel to the welds and the plate. If the pull is not parallel
to the welds and plate, the plate will twist and may break.
There are two types of corrective force that may be
used to pull an attachment: tension and shock force.
Tension is a constant force that can be used to pull an
attachment. A constant pull on a damaged panel will
draw the damage in the direction of the pull. A frame
machine with hydraulic rams or a come-along can
supply a constant force.
A shock force is not constant. Instead, it is applied
as a series of blows. A slide hammer is used to apply
a shock force. There are advantages to each type of
corrective force. A constant force works better on
strong folds, but a shock force is easier to set up and is
adequate for minor damage.
In order to apply corrective force, the ram or
come-along must be hooked up to the vehicle and to
a stationary object. The vehicle must be anchored to
prevent it from moving. Figure 8-17 shows a power post
Figure 8-14. Slide hammer hooks of different sizes can
be used to make various pulls. (Morgan Manufacturing)
Threaded rod
Figure 8-15. To repair this vehicle, a threaded rod has
been placed into the taillight hole and a washer and nut
have been threaded onto the rod. The rod serves as an
attachment for pulling out the damage.
has folding damage on the quarter panel. Lengthening
the panel will correct the damage. The attachment is
made by inserting a threaded steel rod in an existing
taillight hole. A washer and a nut are threaded onto the
end of the steel rod. The corrective force is acting only
on the surface area of the washer. As with hooks, the
Clamp
Pull plates
Figure 8-16. A pull plate is welded to the damaged
portion of this panel. The damage can then be pulled
out with a self-tightening clamp and a hydraulic ram or
a slide hammer.