Pontiac FIREBIRD 1972 Service Manual page 246

Section 2
FRAME AND BODY MOUNTINGS
CONTENTS OF THIS SECTION
Frame Identification
..................................................
2-6
Frame Lift Points
......................................................
2-2
FRAME
A, 6 AND G SERIES
The frames used on the A, B, and G Series are of a swept
perimeter design (Fig. 2-1). The perimeter frame has two
advantages: Frist, the body comes down over the frame
and forms an integrated structure with body sheet metal
contributing greatly to the strength of the car; secondly,
although the body and frame strenthen each other, there
is no metal-to-metal contact, because they are connected
by means of rugged butyl rubber body mounts which
isolate the driver and passenger from engine, transmis-
sion, drive-line, and road disturbances. The B Series sta-
tion wagon frame is of a unique design with the rear
crossmember moved forward to provide clearance for the
glide a-way gate.
F & X SERIES
F
&
X Series frames are of a unitized construction. A
partial frame supports the front end sheet metal, front
suspension, engine, and other mechanical components.
Unitized construction demands that underbody compo-
nents be properly aligned to ensure correct suspension
location. In the event of collision damage it is important
that the underbody be thoroughly checked and, if neces-
sary, realigned in order to accurately established suspen-
sion locations.
HOIST LIFTING POINTS
A,
6 AND G SERIES
Lifting can be accomplished without adapters when using
drive-on, or twin post type hoists, with hoists or lifts mak-
ing contact with front suspension lower control arms or
rear axle. Since the frame is perimeter type, some hoists
designed to contact side rails require adapters to raise the
car without damage to parts of exhaust system, body,
floor, etc. Suppliers of original lifting equipment should
have information on adapters to use on A, B and G Series
cars. Refer to Fig. 2-2 for proper lift point connections.
NOTE: The vehicle should never be lifted by
the rear bwer control arms.
Frame Alignment
......................................................
2-4
Body Bolts
.................................................................
2-5
F & X SERIES
Like the series with swept perimeter type frame, the F &
X Series can be lifted in a similar manner on a twin post
hoist by making contact with the front suspension lower
contorl arms and the rear axle. Since there is a bolted on
stub frame in front and welded side rails at the rear. The
car may also be lifted at the points illustrated in Fig. 2-3.
Proper adapters must be used to prevent damage to the
various parts of the underbody. Caution should be exer-
cised so as not to nick the rear springs.
UNDERBODY ALIGNMENT
The dimensions for X, Y and Z in Figures 2-2 and 2-4 are
not given but are used merely to illustrate points for taking
diagonal measurements for checking squareness of the
frame. Holes or rivet heads are located on the frame at
approximate terminal point of arrowheads, and can be
used for this purpose. Refer to Fig. 2-4 for frame dimen-
sions. For underbody dimensions on the F & X Series refer
to Section 3 or the Body Manual.
I
SEDAN CONVERTIBLE
TYPICAL SIDE BAR SECTION
I
Fig.
2-1
Typical Perimeter Design Frame