Pontiac FIREBIRD 1972 Service Manual page 1161

9-8 1972 PONTIAC SERVICE MANUAL
TROUBLE DIAGNOSIS (Continued)
POWER STEERING GEAR LEAKING OIL EXTERNALLY (Continued)
Follow steps below. If first step is O.K., proceed down list until problem
is corrected.
CAUSE CORRECTION
a. Hose connection loose or hose cracked.
b. Side cover "0" ring seal.
c. Pitman shaft seals.
d. Housing end plug seal.
e. Adjuster plug seals.
f. Torsion bar seal.
g. Defective housing.
a. Tighten connection or replace hose as necessary.
b. Replace seal.
c. Replace seals.
d. Replace seal.
e. Replace seals.
f. Replace rotary valve assembly.
g. Replace housing assembly.
ENERGY ABSORBING STEERING COLUMN
DESCRIPTION
All models incorporate a steering column mounted lock
located on the right-hand side of the steering column im-
mediately below the steering wheel. The system locks the
steering wheel, ignition system, and the transmission shift
linkage when the ignition key is removed from the lock.
Five key positions are provided, each with a positive de-
tent. These positions are, in a clockwise direction, "acces-
sory"
-
"lock"
-
"off'
-
"on"
-
"start" (Fig. 9-3). The
"lock" position is indicated by a groove on the rotating
lock faceplate which aligns with an arrow and embossed
LOCK letters on the column mast jacket. In the "lock"
position, movement of the steering wheel and the trans-
mission shift linkage is restricted and the ignition key can
be removed from the lock. The "off" position permits the
steering wheel and the transmission shift linkage to be
moved normally without having to have the engine run-
ning, but the ignition key cannot be removed from the
lock.
The locking feature is incorporated in the two column
applications available; regular energy-absorbing and tilt
energy-absorbing. The regular column is standard on all
models and the tilt column is optionally available on all
models. The basic functioning of the locking mechanism,
is the same for each column.
Two wing tabs on the lock and use of a large ignition key
head provide operating leverage for turning the lock cylin-
der. A toothed sector on the end of the cylinder inside the
column meshes with a rack such that the rack moves up
or down the column as the lock cylinder is rotated. This
movement is used to lock the steering wheel and transmis-
sion shift linkage (either floor or column mounted) when
the cylinder is rotated to the "lock" position (Fig. 9-4).
A slotted lock plate is splined to the steering shaft upper
end. As the lock cylinder is rotated to the "lock" position,
the lock bolt moves up the column with the rack and into
one of the 12 slots in the lock plate. The lock bolt is spring
loaded so that the wheel will "lock" with any wheel move-
ment if the lock bolt is unable to enter directly into one
of the slots.
A slotted lock bracket moves with the steering column
shifter bowl as the transmission is shifted. When the trans-
mission is in the PARK position on automatic or RE-
VERSE position on manual shift transmissions, the slot in
the lock bracket is aligned such that a raised step on the
rack moves into the slot when the lock cylinder is rotated
to the "lock" position. This effectively prevents the shifter
bowl from moving, thereby preventing the transmission
from being shifted. This also prevents the lock cylinder
Fig. 9-3 Lock Cylinder Positions