After you have inspected, cleaned, and replaced
worn or damaged parts, put the supercharger back
together as prescribed in the manufacturers
maintenance and service manuals. Upon complete
reassembly and after the supercharger is installed
on the engine, add the proper quantity of
recommended engine lubricating oil to the gear
end plate through the pipe plughold.
The turbocharger (fig. 5-38) is a unit that is
driven by exhaust gas to force (charge) air into the
diesel engine cylinders for more complete burning
of fuel and to increase engine power. As with any
air induction component, the turbocharger is
subject to environmental situations that could
result in a turbocharger failure.
The real problem lies not in fixing the failure
but in determining the cause. Replacing a failed
turbocharger without first determining why it
failed will often result in a repeated failure.
There are many causes of turbocharger failure,
but they can be grouped into the following
Lack of lubricating oil
Foreign material or dirt in the lubricating
Foreign material in either the exhaust or air
Material or workmanship
A failure can occur if the lubricating oil being
supplied to the turbocharger is not sufficient to
lubricate the thrust and journal bearings, stabilize
the journal bearings and shaft, and cool the
bearing and journal surfaces, even for periods as
short as 5 seconds.
Operating the engine with contaminated oil
under the assumption that the oil filter will
remove the contaminants before they reach the
bearings of the turbocharger can be quite costly.
Actually, there are certain conditions under which
the oil filter is bypassed and, if the oil is
contaminated, turbocharger damage can result.
Some examples of instances where the filter will
be bypassed areas follows:
The turbocharger lubrication valve is open as
it is in starting.
Figure 5-38.-Turbocharger (cutaway view).