GMC 1982 Light Duty Truck Service Manual page 230

3A-2 FRONT ALIGNMENT
PRELIMINARY CH ECKS PRIOR TO ADJUSTING
FRONT ALIGNMENT
Before making any adjustment affecting caster, cam ­
ber or toe-in, the following checks and inspections should be
made to insure correctness of alignm ent readings and
alignment adjustments.
1. Check all tires for proper inflation pressures and
approximately the same tread wear.
2. Check front wheel bearings for looseness (.001-.008
end play is correct) and adjust if necessary.
3. Check for looseness of ball joints, tie rod ends and
steering relay rods; if excessive looseness is noted, it
must be corrected before adjusting.
4. Check for run-out of wheels and tires.
5. Check dimension A in Fig. 3A-4; if out of specifications
and a correction is to be made, the correction must be
made before adjusting caster.
6. Check for steering gear looseness at frame.
7. Check for improperly operating shock absorbers.
8. Check for loose control arms.
9. Check for loose or missing stabilizer bar attachments.
10. Consideration must be given to excess loads, such as
tool boxes. If this excess load is
vehicle, it should remain in the vehicle during align­
ment checks.
CAMBER ANGLE
FR O N T V IE W
Fig. 3A-1--Caster - Camber - Toe-In
M A IN TEN A N C E A N D ADJUSTMENTS
normally carried in the
OF WHEEL
CASTER ANGLE
SIDE V IE W
11. Consider the condition of the equipment being used to
check alignm ent and follow the m a n u f a c tu r e r's
instructions.
12. Regardless of equipment used to check alignment, the
vehicle must be on a level surface both fore and aft and
transversely.
13. Steering and vibration complaints are not always the
result of improper alignment. An additional item to be
checked is the possibility of tire lead due to worn or
improperly manufactured tires. " L e a d " is the devia­
tion of the vehicle from a straight path on a level road
without hand pressure on the steering wheel. Section
3E of this manual, "Wheels and Tires", contains a
procedure for determining the presence of a tire lead
problem.
FRONT ALIGNMENT REQUIREMENTS
Satisfactory vehicle operation may occur over a wide
range of front end wheel alignment settings. Nevertheless,
should settings vary beyond certain tolerances, readjust­
ments of alignment is advisable. The specifications stated in
column 1 of the chart in the specifications section of this
manual should be used by owners, dealers and repairmen as
guidelines in vehicle diagnosis either for repairs under the
new vehicle warranty or for maintenance service at custom­
er's request. These specifications provide an acceptable all-
around operating range in that they prevent abnormal tire
wear caused by wheel alignment.
DIRECTION