Chevrolet 10 1971 Series, Chassis Service Manual

Page: 10 / 466

LUBRICATION 0-8
Supplemental Engine Oil Additives
The regular use of supplemental additives is specifi­
cally not recommended and will increase operating costs.
However, in cases of specific problems which may arise
under certain conditions, additive supplements are avail­
able that can effectively and economically solve these
problems without causing other difficulties. For example,
if higher detergency is required to reduce varnish and
sludge deposits resulting from some unusual operational
difficulty, a thoroughly tested and approved concentrate—
"Engine Oil Supplement” —is available.
Checking Oil Level
The engine oil should be maintained at proper level.
The best time to check it is before operating the engine
or as the last step in a fuel stop. This will allow the oil
accumulation in the engine to drain back in the crankcase.
To check the level, remove the oil gauge rod (dip stick),
wipe it clean and reinsert it firmly for an accurate read­
ing. The oil gauge rod is marked "FU LL” and "ADD
OIL” . The oil level should be maintained in the safety
margin, neither going above the "FU LL” line nor below
"ADD OIL” line. Reseat the gauge firmly after taking
the reading.
NOTE:
The oil gauge rod is also marked. "Use
GM 6041-M Quality MS oil” as a reminder to use
only high quality oils as prescribed under "E n ­
gine Oil Recommendations.”
Crankcase Capacity (Does not include filter)
292 L6 Engine; 5 quarts U.S. measure, 4.25 quarts
Imperial measure.
All other engines; 4 quarts U.S. measure, 3.25 quarts
Imperial measure.
Engine Oil Change Interval
Change oil each 4 months. If more than 6,000 miles
are driven in a 4-month period, change oil each 6,000
miles.
In the following types of service the oil change interval
should not exceed 2 months, or 3,000 miles, whichever
occurs first.
• operation under dusty conditions,
• trailer hauling or camper use,
• extensive idling,
• frequent long runs at high speeds and high ambient
temperatures,
• short trip operation at freezing temperatures (en­
gine not thoroughly warmed up), or
• STOP and GO type service such as delivery trucks,
etc.
The above recommendations apply to the first change
as well as subsequent oil changes. The oil change in­
terval for the truck engine is based on the use of oils
that meet the requirements indicated in the section on
"Engine Oil Recommendations.” Oil change intervals
longer than those listed above will result in serious re­
ductions in engine life and may affect Chevrolet's obliga­
tion under the provisions of the new vehicle warranty.
A high quality MS oil meeting General Motors Standard
GM 6041-M was installed in the engine at the factory. It
is not necessary to change this factory-installed oil prior
to the recommended normal change period. However, the
oil level should be checked more frequently during the
break-in period since somewhat higher oil consumption
is normal until the piston rings become seated.
Recommended Viscosity
The following chart will serve as a guide in selecting
the proper oil viscosity. The proper viscosity helps as­
sure good cold and hot starting by reducing friction and
thus increasing cranking speed.
• SAE 5W-20 oils are not recommended for sustained
high speed driving.
• SAE 30 oils may be used at temperatures above
40°F.
RECOMMENDED SAE VISCOSITY NUMBER
10W, 5W-30, 10W-30, 10W-40
w m
m
- 3 0 - 2 0 0 20 4 0 6 0 8 0 100
TEMPERATURE RANGE ANTICIPATED BEFORE NEXT OIL CHANGE, °F.
Fig. 3— O il Viscosity Guide
Engine Oil Filter Replacement
Replace filter at first oil change and at every second
oil change thereafter. This recommendation is based on
the use of engine oils that meet the requirements indi­
cated in the section on "Engine Oil Recommendations,”
and the use of the applicable A.C. oil filter or equivalent.
Oil Filter Type and Capacity
—Throwaway type, 1 quart
U.S. measure, .75 quart Imperial measure.
AIR CLEANER CARE
CAUTION:
In addition to its function of filtering
air drawn into the engine through the carburetor,
the air cleaner also acts as a flame arrestor in
the event the engine backfires. Because back­
firing may cause fire in the engine compart-
ment, the air cleaner should be installed at all
times unless its removal is necessary for re-
pair or maintenance services.
NOTE:
Under prolonged dusty driving condi­
tions, it is recommended that these operations
be performed more often.
Paper Element Type
First 12,000 miles, inspect element for dust leaks,
holes or other damage, replace if necessary. If satis­
factory, rotate element 180° from originally installed
position. Replace element at 24,000 miles. Element
must not be washed, oiled, tapped or cleaned with an air
hose.
Oil Wetted Paper Element Type
The oil wetted paper element is a long-life efficient
air cleaner and should not require replacement before
24,000 miles except under extremely dusty conditions.
10-30 CHEVROLET TRUCK SERVICE MANUAL