INTRODUCTION TO THE HMMWV - OD1615 - LESSON 1/TASK 2
cylinder walls is severe, making effective lubrication of this area
imperative. Lubrication of the connecting rod and main bearings is crucial
because of the heavy loads that are placed on them. There are many other
less critical engine parts such as the camshaft, valve stems, rocker arms,
and timing chains that also need a constant supply of oil.
(2) Oil as a Coolant.
Engine oil circulated throughout the engine
also serves to remove heat from the friction points.
The oil circulates
through the engine and drains to the sump. The heat picked up by the oil
while it is circulated is removed by an airflow around the outside of the
sump. In some instances where the sump is not exposed to a flow of air, it
is necessary to add an oil cooling unit that transfers the heat from the oil
to the engine cooling system through an oil cooler mounted in front of the
radiator. The HMMWV has this type of cooler.
b. Characteristics and Operation of the HMMWV's Lubrication System.
pressure may drop down to 15 psi.
filter) contains 7 quarts, 8 quarts with the filter.
There are three different weights of oil that are used in the HMMWV engine,
depending under what temperature the vehicle is expected to operate. If the
temperature is above 40 F, then heavy duty engine oil (OE/HDO 30) is used;
if the temperature ranges between 40 F to -15 F, then OE/HDO 10 oil is
used; if the temperature falls between -15 F to -65 F, an arctic type
engine oil (OEA) must be used.
filter, gear-driven oil pump, and an oil cooler. The pump is mounted on the
rear main bearing cap. Oil is picked up by a tube and is pumped to the oil
cooler. The oil cooler is mounted in front of the radiator. The oil then
flows from the oil cooler to the oil filter, located on the left side of the
engine. The oil filter is of the cartridge-type and all oil going to the
engine must first pass through it.
This type of filter is also called a
full flow filter.