RUBBING OR BINDING IS FELT WHEN TUBEAXIAL FAN BLADES OR LEFT COOLING FAN BLADES ARE TURNED BY HAND AND MORE THAN ONE HALF OF ACCESSORY GEARBOX (AGB)

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CONTINUED

3-2. TROUBLESHOOTING

k . POWER TURBINE AND REDUCTION

(5)

ES-44. RUBBING OR BINDING IS

GEARBOX (RGB) - CONTINUED

F E L T WHEN TUBEAXIAL FAN BLADES

O R LEFT COOLING FAN BLADES ARE

TURNED BY HAND AND MORE THAN

ONE HALF OF ACCESSORY GEARBOX

( A G B ) AND MAIN OIL PUMP MAGNETIC

PLUGS ARE COVERED WITH METAL

CHIPS.

thls section contalns troubleshootng to locate and correct the cause(s)

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

blades are turned by hand, when more than one half of the AGB and main

oil pump magnetic plugs, are covered with metal chips. The power turbine

and RGB are coupled mechanically through the power shaft. If there is

damage to the power turbine, rear engine subassembly position No. 6A or

6B bearing, or RGB bearings and/or gears, binding w1ll be felt when the

tubeaxial fan blades or left cooling fan blades are turned by hand. The

AGB acts as an oil sump to collect oil scavenged from bearings in the

forward engine module and rear engine subassembly. The main oil pump

pumps the hot oil from the sump to the engine oil cooler. 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 symptoms described above indicate a

damaged rear engine subassembly and RGB. 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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