5-36.
To reduce torsional fluctuations and
5-43.
ensure smoother operation, some diesel
engine crankshafts are equipped with
which of the following devices?
1.
Vibration dampers
2.
Flexible couplings
3.
Shock absorbers
4.
Flywheels
5-37.
Which of the following lubricants is/are
harmful to the rubber of elastic-type
vibration dampers?
5-44.
1.
Lube oil
2.
Diesel oil
3.
Light grease
4.
All of the above
5-38.
Which of the following engine noises
indicates an improperly functioning
vibration damper?
1.
Grinding noises at low speeds
2.
Clinking noises during starting
3.
Rumbling noises at normal speeds
4.
Humming noises at high speeds
Question 5-39 is to be judged True
or False.
5-39.
Crankshaft failure may result from
excessive main bearing clearances that
allow an uneven distribution of the
engine load during operation.
5-40.
You can help keep engine journal bearings
from wearing out-of-round by preventing
which of the following conditions?
1.
Inadequate lubrication and journal
bearing failure
2.
Overloading or overspeeding of the
engine
3.
Excessive crankshaft deflection and
misalignment of parts
4.
All of the above
5-41.
5-42.
Which of the following actions is likely
to cause excessive crankshaft deflection?
1.
Overloading
2.
Overspeeding
3.
Insufficient lubrication
4.
Excessive operating temperatures
What valve assembly trouble is likely to
score the camshaft cams of an engine?
1.
A worn rocker arm bushing
2.
A broken tapped screw
3.
A chipped valve spring
4.
An improperly seated push rod spring
Which of the following inspections to the
valve actuating linkage should be made at
frequent intervals during engine
operation?
1.
Inspections for improperly seated
valve springs
2.
Inspections for grooved or scored
cam follower surfaces
3.
Inspections for improperly seated
push rod end fittings
4.
All of the above
What is the danger in using an engine
lubricating oil that has a viscosity
higher than recommended?
1.
Rapid absorption of acids
2.
Rapid absorption of carbon particles
3.
Surface pitting of bearings
4.
Overlubrication
Question 5-45 is to be judged True or
False.
5-45.
When a bearing fails because of an
inadequate bond between the bearing metal
and the bearing shell, the bearing shell
shows through the bearing surface.
5-46.
Crankshaft journals that exceed the
specified tolerances for out-of -roundness
should be refinished by which of the
following means?
1.
Stoning
2.
Grinding
3.
Filing
4.
Scraping
5-47.
A rough spot or ridge located on a crank
pin journal should be removed by dressing
with which of the following materials?
1.
4 fine sandpaper
2.
A crocus cloth
3.
A fine oil stone
4.
Both 2 and 3 above
5-48.
What damage may result to a crank pin
bearing when the piston bushing bore and
connecting rod bore are not in alignment?
1.
Cracking at the opposite ends of the
lower and upper halves
2.
Cracking at the same ends of the
lower and upper halves
3.
Wiping at the opposite ends of the
lower and upper halves
4.
Wiping at the same ends of the
lower and upper halves
32