Chevrolet 1980 Light Duty Truck Service Manual page 16

OB-6 M AIN TEN A N C E AND LUBRICATION
Fig. 0B -5 ~A u tom atic Transm ission D ipstick
lubricant.
Rear Axle (Limited-Slip) Lubricant
Check lubricant level. Add lubricant, if necessary, to
fill to level of filler plug hole. Use gear lubricant GM
1052271/1052272 or equivalent.
Autom atic Transmission Fluid
Use only automatic transmission
DEXRON®-II or equivalent.
Check the automatic transmission fluid level at each
engine oil change period. Overfilling can cause foaming and
loss of fluid. Transmission damage can result. Low fluid
level can cause slipping or loss of drive.
Automatic transmissions are often overfilled because
the fluid level is checked when the fluid is cold. When cold,
the dipstick shows that fluid should be added. However, the
low reading is normal, the level will rise as the fluid gets
warm. The fluid level will increase more than 3/4 inch
(19mm) as fluid warms up from 60°F to 180°F (16°C to
82°C).
Check the transmission fluid level with the engine
running, the shift lever in "Park", and the vehicle level.
If the vehicle has just been driven for a long time at
high speed or in city traffic in hot weather, or if the vehicle
has been pulling a trailer, the correct fluid level cannot be
read. Wait until the fluid has cooled down (about 30
minutes).
Remove the dipstick. Carefully touch the wet end of
the dipstick to find out if the fluid is cool, warm or hot. Wipe
it clean and push it back in until cap seats. Pull out the
dipstick and read the fluid level (fig. 0B-5).
• If it felt cool, about room temperature, the level
should be 1/8 to 3/8 inch (3 to 10mm) below the "Add"
mark. The dipstick has two dimples below the "Add" mark
to show this range.
• If it felt warm, the level should be close to the "Add"
mark (either above or below).
• If it was too hot to hold, the level should be at the
"Full" mark.
• It takes only one pint (0.5 liter) to raise level from
"Add" to "Full" with a hot transmission.
M anual Transmission Lubricant
Check lubricant level. Add lubricant, if necessary, to
fill to level of filler plug hole.
Use SAE 80W GL-5 or SAE 80W-90 GL-5 gear
lubricant. For those vehicles driven in Canada, use SAE
80W GL-5 gear lubricant.
W indshield W asher Fluid
(Also a Safety Service)
Fill the washer jar only 3/4 full during the winter to
allow for expansion if the temperature should fall low
enough to freeze the solution.
• Check the washer fluid level regularly-do it often
when the weather is bad.
• Use a fluid such as GM Optikleen or equivalent to
help prevent freezing damage, and for better cleaning.
• Do not use radiator antifreeze in the windshield
washer; it could cause paint damage.
• In cold w eather, w arm the windshield w ith
the defrosters before using the washer--to help
prevent icing th a t may block the driver's vision.
Cooling System Care
Do not remove radiator cap to check coolant level.
Instead, check by looking at the "see through" coolant
recovery tank. Level should be at the "Full Cold" mark on
fluid labeled
the recovery tank when the system is cold; and at the "Full
Hot" mark during engine operation. Add a
of a good quality ethylene glycol antifreeze and water to the
recovery tank when more coolant is needed. If frequent
additions are needed, cooling system.
NOTICE:
is no need to add extra inhibitors or additives that claim
to improve the system. They may be harmful to the
proper operation of the system, and are an unnecessary
expense.
A-2 M anual Transmission Clutch Adjustm 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 to one and a half inches; if very
little or no free travel is evident, clutch adjustment is
required.
A-3 & A-6 Engine Oil and Filter
(Also an Emission Control Service)
Engine Oil and Filter Recommendations
Gasoline
• Engine oils are labeled on the containers with various
API (American Petroleum Institute) designations of
quality. Use engine oils that are labeled SE, SF or SE/CC.
Do not use oils labeled only SA, SB, SC, SD, CA, CB, CC
or CD; or oils with the combination label SE and CD (SE/
CD).
• Use only SE or SF quality engine oils (see markings
on containers).
• The oil and filter change intervals for the engine is
based on the use of SE-quality or SF-quality oils and high
quality filters. Using oils other than SE-quality or SF-
quality oils, or oil change intervals longer than listed, could
reduce engine life and might affect warranty.
• The engine was filled with an SE or SF quality engine
oil when it was built. You do not have to change this oil
before the suggested change period.
• Change oil each
year for light duty emissions service, each
km) or 4 months for heavy duty emissions service,
If the proper quality antifreeze is used, there
miles (12
7,500 000
6,000
LIG H T DUTY T R U C K S ER V IC E M AN UAL
mixture
50/50
km) or once a
miles (9
600