GMC 1982 Light Duty Truck Service Manual page 18

F R O N T
4 W H E E L R O T A T IO N
PREFERRED
D O N O T IN C L U D E " T E M P O R A R Y U S E O N L Y "
S P A R E T IR E IN R O T A T IO N
* T H E O P T IO N A L 'X ' R O T A T IO N P A T T E R N FOR
R A D IA L S IS A C C E P T A B L E W H E N R E Q U IR E D
FO R M O R E U N IF O R M T IR E W E A R
Fig. 0B-9-Tire Rotation
Checking Oil
• Warm- The best time to check the engine oil level is
when the oil is warm, such as during a fuel stop. First,
allow about 5 m inutes
back to the oil pan. Then pull the dipstick out, wipe it
clean, and push it back down all the way. Now pull the
dipstick out and look at the oil level on the dipstick.
Some dipsticks are marked with " A d d " and "F ull"
lines. Others are marked "A dd 1 Q t" and "Operating
Range ". In all cases, keep the oil level above the " Add "
line. Push the dipstick back down all the way after
taking the reading. Add oil if needed.
• Cold- If you check the oil level when the oil is cold, do
not run the engine first. The cold oil will not drain back
to the pan fast enough to give a true oil level.
A -4 M a n u a l Transmission Clutch A djustm ent
Clutch adjustment should be checked and adjusted as
necessary to compensate for clutch facing wear. To check,
depress pedal by hand until resistance is felt. Free travel
should be approximately one inch; if very little or no free
travel is evident, clutch adjustm ent is required.
A -5 Steering and Suspension
Inspect .front and rear suspension and steering system
for damaged, loose or missing parts, signs of wear or lack of
lubrication. Inspect power steering lines and hoses for
proper hook-up, binding, leaks, cracks, chafing, etc. When
rubbing or wear is noted on hoses or lines, the cause must be
corrected at once.
Front Suspension and Steering Linkage
(a) On C20 and G30, lubricate every 4 months or 6,000
miles (9 000 km).
(b) On all other vehicles, lubricate very 12 months or
7,500 miles (12 000 km).
(c) Lubricate suspension and steering linkage every 3
months or 3,000 miles (4 800 km) when operating under
dusty or muddy conditions and in extensive off-road use.
F R O N T
4 W H E E L R O T A T IO N
O P T IO N A L
1 0 0 8 5
for the oil to drain
MAINTENANCE AND LUBRICATION
A -6 Exhaust System
Inspect the complete exhaust system, including the
catalytic converter. Inspect body areas near the exhaust
system and also the tailgate. Look for braken, damaged,
missing or out-of-position parts. Also, inspect for open
seams, holes, loose connections, or other conditions which
could cause a heat buildup in the floor pan, or could let
exhaust fumes seep into the passenger compartment. Dust
or water in the passenger compartment may indicate a leak
in the area. Make needed repairs at once. To help maintain
system integrity, replace the exhaust pipes and resonators
rearward of the muffler whenever a new muffler is installed.
A -7 Tires
Inspection a n d Rotation
Front and rear tires perform different jobs and can
wear differently depending on the types of roads driven,
driving habits, etc. To obtain maximum tire life inspect and
rotate tires regularly. (Fig. 0B-9) If the truck is equipped
with tires having different load ratings between the front
and the rear, the tires should not be rotated front to rear.
Vehicle handling could be adversely affected and the tires
having the lower load rating could be overloaded.
C A U TIO N : Before installing w heels, rem ove a n y
b u ild up of corrosion on th e w h e e l m o u n tin g
surface a n d brake drum or disc m ounting surface
by scraping a n d w ire brushing. Installing w h e e l
w ith o u t good m e ta l-to -m e ta l contact a t th e
m ounting surfaces can cause the w h e e l nuts to
loosen, w hich can later a llo w a w h e e l to come off
w h ile the vehicle is m oving, possibly causing loss
of control.
Inflation Pressure
The cold inflation pressures for the factory installed
tires are on the label on the rear of the driver's door The tires
must be inflated to these pressures to obtain the G V W R
(Gross Vehicle Weight Rating) or G A W R (Gross Axle
W eight Rating). Incorrect tire inflation pressures can have
adverse effects on tire life and vehicle performance. Too low
an air pressure causes increased tire flexing and heat build­
up. This weakens the tire and increases the chance of
d am age or failure and can result in tire overloading,
PROPERLY INFLATED PROPERLY INFLATED
BIAS
OR BIAS-BELTED TIRE
Fig. 0B-10--Properly Inflated Tire
OB-9
IMPROPERLY INFLATED
J
I
Y
—
RADIAL TIRE