Chevrolet 1980 Light Duty Truck Service Manual page 217

TURN", "RIGHT TURN", "KEY BUZZER", and
"HAZARD". (Trucks do not incorporate a Key Buzzer
Switch) if the systems function properly while using the
tester, then the malfunction has been narrowed to the
column wiring or components. When this has been
determined then the column may be serviced to correct the
malfunction.
To use the tool just unfasten the harmonica connector
on the column and plug the harness from J-23980 into the
vehicle chassis harness. The "A", "B", and
on the tester will overhang the chassis connector. This does
not affect the test results. These terminals are for vehicles
with cornering lights. Connect the single black jumper to
a good ground. The tester is now ready for use (Fig. 3B4-2).
COLLISION D IAG NO SIS (FIGS. 3B4-3
THROUGH 3B4-8)
To determine if the energy absorbing steering column
components are functioning as designed, or if repairs are
required, a close inspection should be made. An inspection
is called for in all cases where damage is evident or whenever
the vehicle is being repaired due to a front end collision.
Whenever a force has been exerted on the steering wheel or
steering column, or its components, inspection should also
be made. If damage is evident, the affected parts must be
replaced.
The inspection procedure for the various steering
column components on C and K trucks is as follows:
Column Support Bracket
Damage in this area will be indicated by separation of
the mounting capsules from the bracket. The bracket will
have moved forward toward the engine compartment and
will usually result in collapsing of the jacket section of the
steering column.
C O LUM N JACKET
Inspect jacket section of column for looseness, and/or
bends.
SHIFTER SHAFT
Separation of the shifter shaft sections will be internal
and cannot be visually identified. Hold lower end of the
"shifter shaft" and move "shift lever" on column through
terminals
"C"
its ranges and up and down. If there is little or no movement
of the "shifter shaft", the plastic joints are sheared.
Steering S haft
If the steering shaft plastic pins have been sheared, the
shaft will rattle when struck lightly from the side and some
lash may be felt when rotating the steering wheel while
holding the rag joint. It should be noted that if the steering
shaft pins are sheared due to minor collision with no
appreciable damage to other components, that the vehicle
can be safely steered; however, steering shaft replacement
is recommended.
Because of the differences in the steering column types,
be sure to refer to the set of instructions below which apply
to the column being serviced.
M ETHO D TO DETERMINE CO LUM N
COLLAPSE
Measure distance between top of neutral-start switch
window opening and the bottom of the upper jacket. The
correct value is shown below:
a. C-Truck 5 11/16" to 5 1/2".
b. K-Truck 5 11/16" to 5 1/2".
STEERING CO LUM NS
LIG H T T R U CK SfcRVICt M AN UAL
3B4-3