LOW PRESSURE COMPRESSOR RUBS OR BINDS WHEN TURNED BY HAND-continued

TM 9-2835-255-34

3-2. TROUBLESHOOTING - CONTINUED

(8) ES-35. LOW PRESSURE COMPRESSOR

h. LOW PRESSURE COMPRESSOR -

RUBS OR BINDS WHEN TURNED BY

CONTINUED

HAND, RUBBING OR BINDING IS FELT

WHEN TUBEAXIAL FAN BLADES OR

LEFT COOLING FAN BLADES ARE

TURNED BY HAND AND THERE ARE

METAL CHIPS IN THE OIL PUMP TO

OIL COOLER FLUID FILTER.

This section contains troubleshooting to locate and correct the cause(s)

of low pressure compressor rubbing or binding when turned by hand, and

rubbing or binding when the tubeaxial fan blades or left cooling fan

blades are turned by hand, when there are metal chips in the oil pump to

oil cooler fluid filter. The low pressure compressor is mechanically

coupled to the low pressure turbine rotor in the rear engine

subassembly. I f t h e r e i s d a m a g e t o t h e l o w p r e s s u r e c o m p r e s s o r o r

position No. 1 or 2 bearing in the forward engine module, or to the low

pressure turbine rotor or position No. 5 bearing in the rear engine

subassembly, binding will be felt when the low pressure compressor i s

turned by hand. The power turbine and reduction gearbox (RGB) are

coupled mechanically through the power shaft. If there is damage t o t h e

power turbine, rear engine subassembly position No. 6A or 6B bearing, or

RGB bearings and/or gears, binding will be felt when the tubeaxial fan

blades or left cooling fan blades are turned by hand. The RGB oil return

line feeds directly into the oil pump passage that houses the magnetic

plug. The only possible source of metal chips on the oil pump magnetic

plug is the RGB. The lubrication system delivers hot oil, scavenged from

bearing packages throughout the engine, t h r o u g h a f l u i d f i l t e r t o t h e

engine oil cooler. The cooled oil is then returned to the oil tank.

Whenever metal chips are generated, t h e f l u i d f i l t e r w i l l c a t c h a n d

retain most of the chips. The art on the following pages provides an

overview of the systems described above. Refer to these pages along with

in-text art while performing troubleshooting.

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