Chevrolet 70 1969 Series, Shop Manual

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LUBRICATION 0-9
1. Engine oil be drained initially after the
first 100 hours of operation. On highway vehicles
this corresponds to approximately 2,000 miles of
service. The drain interval may then be gradually
increased or decreased. Following the recom­
mendations of the oil supplier (based on analysis
of the drained oil) until the most practical oil and
filter element change period for the particular
service has been established. For vehicles oper­
ating exclusively in highway service, extended
intervals may be permissible, while vehicles
operating in "city-service" may require more
frequent oil changes.
2. Solvents should not be used as flushing
oils. Dilution of the fresh refill oil supply can
occur which may be detrimental.
G A SO LIN E EN GIN E
Use only high quality oils which are:
(1) Intended for Service Designations " M S ”
and " D M ” ^see N O T E ).
-or-
(2) Products passing vehicle manufacturers
tests (including General Motors Standard
G M 6042M).
N O T E : Supplement 1 engine oils (based upon
now obsoleted MIL-L-2104A) have been super­
seded by MIL-L-2104B engine oils. However,
Supplement 1 engine oils (MS-DM) with a history
of satisfactory performance are available, and
may be used.
The use of proper engine oils and oil change
intervals are your best assurance of continued
reliability and performance from your Chevrolet
engine.
IM P O R T A N T : Non-detergent and other lower
quality engine oils are specifically not recom­
mended in gasoline engines.
Gasoline Engine Oil Change Periods:
It is recommended that the engine crankcase
oil be initially drained and refilled with new oil
after the first 2,000 miles of service. Thereafter,
the intervals at which crankcase oil should be
changed depend entirely upon the type and quality
of oil used, the severity of truck operation, and the
mechanical condition of the engine. 2,000 mile
change intervals are suggested, as these intervals
are compatible with the 6,000 mile chassis lubri­
cation intervals. However, different intervals may
be necessary, depending upon operating and temp­
erature conditions as explained following:
In highway freight haul with very little idling
and/or cold operation, while using MIL-L-2104A
or API Service ”D G " (N O T E 2) oils, drain crank­
case every 2,000 miles or 60 days, whichever
comes first and change filter every 2,000 miles or
every 2 months, whichever occurs first (N O T E 1
following).
When operating in variable or intermittent low
temperature where use of " D G " oil has resulted in
some sludge and/or varnish formation, use "Sup­
plement 1" (API Service " D M " ) (N O T E 3) and drain
crankcase every 2,000 miles or 6 0 days, whichever
comes first, and change filter every 2,000 miles or
every 2 months, whichever occurs first (N O T E 1).
Series 3 (API Service "D S ") engine oils should
hot be used in Chevrolet gasoline engine, except
upon recommendation of the oil supplier.
N O T E 1 - Use of independent laboratory oil
analysis reports or oil supplier recommendation
(based upon oil sample analysis) should be made to
determine if more or less frequent oil and filter
change periods are required, or possible.
N O T E 2 - Some oil suppliers may designate
as "M S- D G ."
N O T E 3 - Some suppliers may designate as
"M S- DG- DM ."
B R EAK - IN OILS A N D AD DITIVES
The use of proprietary blends of supplement­
ary additives or concentrates such as engine oil
supplements, break-in oils, tune-up compounds,
friction reducing compounds, etc., is not recom­
mended in lubricating oils of the Diesel engines in
Chevrolet Trucks. A lubricating oil additive is
available from Chevrolet dealers specifically for
gasoline engines.
VISCOSITIES
Atmospheric temperatures and severity of
service determine the viscosity grade of engine oil
to use. Viscosity numbers constitute a classifica­
tion of lubricants in terms of viscosity or fluidity,
but with no reference to any other characteristics
or properties.
As a guide to the selection of the proper grade
or viscosity of oil to be used at various atmos­
pheric temperatures, refer to respective gasoline
or Diesel engine "Viscosity Chart" (figs. 5 and 6).
If cold starting is a problem the use of lighter
oils will lessen such starting difficulties.
M ULTI- VISCOSITY T Y PE EN G IN E OILS
Multi-Viscosity lubricating oils, as a group,
are not normally recommended. However, some
may be effectively used to facilitate starting when
prolonged exposure of the engine to temperatures
below freezing is unavoidable. Consult your sup­
plier regarding the performance characteristics of
this type of oil and obtain his assurance of adequate
lubrication before subjecting the engine to heavy-
duty service.
CHECKING ENGINE OIL LEVEL
Daily, or oftener if necessary, check oil level.
Make the check preferably after a day's run and
CHEVROLET SERIES 70-80 H EAVY DUTY TRUCK SH O P M A N U A L