64 Section 1 Introduction to Collision Repair
N O T E
In some unibody vehicles, the drive train is mounted in an
engine cradle. The engine cradle is similar in construction
to a full frame and is bolted to the unibody, Figure 3-19.
The engine, transmission, front suspension, and in some
cases, the steering system are attached to the engine
cradle. If the cradle is damaged, it can be replaced. The
engine cradle may be made out of steel or aluminum.
The center section of a unibody vehicle consists of the
cowl; floor; rocker panels; front, center, and rear pillars;
and roof. The cowl, or firewall, forms the front portion of
the passenger’s compartment. The windshield pillar, r r also
called the A pillar, is a structural part. It is a steel channel that
consists of inner and outer panels and an internal reinforce-
ment. The A pillar is welded in place. The A pillar portion of
the cowl is where the front door hinges are mounted. The
cowl is one of the strongest assemblies in the vehicle.
The center pillar, or B pillar, which is found on r r
four-door vehicles, is the part onto which the front door
latches and the rear door hinges are connected. Center
pillars are channels that are welded to the floor and roof.
The floor pan is the base of the passenger compart-
ment. It is welded to the rocker panel and cowl. The floor
pan has reinforced areas to which the seat belt anchors
are mounted.
The rear pillar is the inner portion of the quarter r
panel. The door latches on the rear pillar. On a four-door
vehicle, the rear pillar may be called a C pillar. The
C pillar may form the inner reinforcement for the sail
panel. The C pillar is welded to the floor and the roof.
Figure 3-19. This engine cradle provides additional support
for the drive train and front suspension components. (Ford)
Figure 3-18. Inner body assemblies found on a typical unibody vehicle. (Ford)
Rear pillar
Windshield
pillars
Upper frame
rails
Rear pillar Rocker
panel
Center
pillars
Strut
towers
Lower
frame rails
Radiatoro Radiat
support t
The rear section is formed by the rear pillars, rear
frame rails, wheel houses, floor, and rear body panel.
See Figure 3-20. The rear frame rail, which provides
support for the rear portion of a unibody vehicle, is a
channel consisting of inner and outer panels and possibly
a reinforcement. The rear suspension may be mounted to
the rear frame rails. A wheel house surrounds the rear e
wheel. It is formed from two panels, an inner panel and an
outer panel, that are welded together. The outer portion
of the wheel house is welded to the quarter panel. The
trunk floor is welded to the inner wheel house panels r
and to the rear frame rails. The rear suspension may be
Unibody
Engine g
dle cr ad