Dodge RAM TRUCK 1500 1995 Service Manual page 38

I - 2 LUBRICATION AND MAINTENANCE
CAPTION: UNLEADED FUEL ONLY must be used in
vehicles equipped with a catalyst emission control
system. All vehicles have reminders printed on the
instrument panel below the fuel gauge and on the
fuel filler door. The vehicles also have fuel filler
tubes that are specially designed to accept only the
small-diameter dispensing nozzles. It is illegal to
bypass the design of an unleaded fuel filler tube
and contaminate the fuel system.
DIESEL ENGINES
The Cummins Diesel engine and its fuel system are
compatible with, and have been designed to operate
with low sulfur diesel fuels. The use of diesel fuel
additive to increase fuel lubricity is not re­
quired or recommended. Diesel fuel lubricity addi­
tives will not damage the 5.9L engine, but will add
unnecessary expense to the operation of the vehicle.
Cummins Turbo Diesel engines require number 2
diesel fuel for operation in most climates. Refer to
Group 14, Fuel Systems for fuel recommendations.
CLASSIFICATION OF LUBRICANTS
Lubricating fluids and chassis lubricants are clas­
sified according to standards recommended by the:
® Society of Automotive Engineers (SAE).
• American Petroleum Institute (API).
• National Lubricating Grease Institute (NLGI).
ENGINE OIL
API CERTIFICATION MARK
For maximum engine protection during all driving
conditions, install an engine oil that contains the API
Certification Mark (Fig. 2). The API Certification
Mark indicates that the oil is certified to meet the
most critical requirements established by the manu­
facturer.
Conformance to API specifications is determined by
tests that measure the ability of an oil to control:
• Engine wear.
• Bearing corrosion.
• Sludge.
• Varnish.
• Oil thickening.
• Rust.
• Piston deposits.
SAE VISCOSITY GRADE
An SAE viscosity grade is used to specify the vis­
cosity of engine oil. SAE 30 specifies a single viscos­
ity engine oil. Engine oils also have multiple
viscosities. These are specified with a dual SAE vis­
cosity grade which indicates the cold-to-hot tempera­
ture viscosity range.
9400-9
Fig. 2 The API Engine Oil Certification Mark
API SERVICE GRADE CERTIFIED
The API Service Grade specifies the type of perfor­
mance the engine oil is intended to provide. The API
Service Grade specifications also apply to energy con­
serving engine oils.
Use an engine oil that is API Service Grade Certi­
fied or an oil that conforms to the API Service Grade
SH or SH/CD. MOPAR provides engine oils that con­
form to all of these service grades.
GEAR LUBRICANTS
A dual grade is also used to specify the viscosity of
multi-purpose gear lubricants.
The API grade designation identifies gear lubri­
cants in terms of recommended usage.
CHASSIS AND WHEEL BEARING LUBRICANTS
The chassis and wheel bearing lubricants that are
recommended are identified by the NLGI Certifica­
tion Symbol. The symbol contains a coded designa­
tion. This identifies the usage and quality of the
lubricant.
The letter G within the symbol designates wheel
bearing lubricant. The letter L designates chassis lu­
bricant. When the letters are combined, the lubricant
can be used for dual applications. Use only lubricants
that display the NLGI Certification Symbol (Fig. 3).
NATIONAL LUBRICATING
GREASE INSTITUTE
NLGI
AUTOMOTIVE
WHEEL BEARING & CHASSIS
LUBRICANT
GC
NATIONAL LUBRICATING
GREASE INSTITUTE
NLQI
AUTOMOTIVE
WHEEL BEARING & CHASSIS
LUBRICANT
LB
NATIONAL LUBRICATING
GREASE INSTITUTE
NLQI
AUTOMOTIVE
WHEEL BEARING & CHASSIS
LUBRICANT
QC-LB
WHEEL
BEARINGS
CHASSIS
LUBRICATION
CHASSIS AND
WHEEL BEARINGS
9200-7
Fig. 3 NLGI Lubricant Container Certification/
Identification Symbol
LUBRICATION AND REPLACEMENT PARTS
RECOMMENDATION
Chrysler Corporation vehicles are engineered to
provide many years of dependable operation. How­
ever,' lubrication service and maintenance are re-