ARMY TM 9-6115-604-12
NAVY NAVFAC P-8-633-12
Install the rocker housing covers in accordance with paragraph 3-14 Remove barring tool and Install clip in
4-82. INSPECT VIBRATION DAMPER. The vibration damper is a counter balance located at the front of the engine
crankshaft used to smooth out critical engine vibrations.
Be careful not to mistake engine lubricant leakage from the crankshaft seal for vibration damper leakage.
The vibration damper Is filled with a thick, heavy, viscous fluid, while engine lubricant flows freely.
Visually Inspect the vibration damper for dents and evidence of fluid leakage Check the pulley for excessive or uneven
wear of the belt surface
4-83. MAINTENANCE OF TURBOCHARGERS. Turbochargers provide additional air flow to cylinders to increase
Remove the hose clamps (6, Figure 4-60) and molded rubber adapter (7) from the air inlet of the turbocharger
Remove "V" band clamp (8) and turbine exhaust connection (9).
Examine the turbocharger assembly (17) for cracked or chipped vanes.
Rotate the rotor by hand while feeling and listening for evidence of bearing roughness or rotor rub. Create a
back-and-forth loading on bearings to remove end play while checking.
A thin, even coating of oily dust on the compressor wheel, and a thin, even coating of car- bon
on the turbine wheel is normal and should not be disturbed. Disturbance of these coatings may
upset the balance of the rotor assembly..
Examine compressor wheel and turbine wheel for excessive buildup of dirt or carbon deposits.
Mount a dial indicator on the air inlet flange of the turbocharger and center the indicator button on the rotor
Move the rotor assembly back and forth to check the total end clearance Total end clearance must not exceed
0 009 inches (0.23 mm).
If turbocharger Is satisfactory, remove the dial indicator, and replace turbine exhaust connection (9), V band
clamp (8), molded rubber adapter (7), and hose clamps (6).
Do not place hands or allow other personnel to place hands near the rotating vanes of the
compressor wheel. Serious injury or dismemberment could occur.
(9) Restart the engine and apply load when available.
(10) Ensure all connections and piping are not leaking.
Do not mistake the normal whine of turbocharger operation for bearing squeal or rotor rub.
(11) Listen for high pitched bearing noise or sounds of compressor wheel or turbine wheel rub.
(12) Observe exhaust for excessive blue smoke Blue smoke from one exhaust stack may indicate defective
(13) Shut down engine immediately If unusual noises are heard or blue smoke is abnormal.
(14) If any defects are noted during the performance of the above steps, remove the turbocharger in accordance
with step b, below Refer defective turbocharger to the next higher level of maintenance.