AGB GEAR TRAIN TURNS UNEVENLY (BINDS) WHEN TURNED BY HAND, RUBBING OR BINDING IS FELT WHEN TUBEAXIAL FAN BLADES OR LEFT COOLING FAN BLADES ARE TURNED BY HAND

TM 9-2835-255-34

3 - 2 . TROUBLESHOOTING - CONTINUED

a . ACCESSORY GEARBOX (AGB) AND

( 9 ) ES-9.

AGB GEAR TRAIN TURNS

HIGH PRESSURE COMPRESSOR -

U N E V E N L Y (BINDS) WHEN TURNED BY

CONTINUED

H A N D , RUBBING OR BINDING IS FELT

WHEN TUBEAXIAL FAN BLADES OR

L E F T COOLING FAN BLADES ARE

TURNED BY HAND AND MORE THAN ONE

H A L F OF AGB MAGNETIC PLUG IS

C O V E R E D WITH METAL CHIPS.

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

of AGB gear train binding when turned by hand, and 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 magnetic plug is covered with

metal chips. The AGB is coupled to the high pressure compressor in the

forward engine module through a gearshaft. If there is damage to the

high pressure compressor, forward engine module position No. 3 or 4

bearing, or AGB gears and/or bearings, binding w1ll be felt when the AGB

gear train is turned by hand. The power turbine and reduction gearbox

(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

transmission is mechanically coupled to the RGB through a splined shaft.

If there is internal transmission damage, binding will be felt when

turning the tubeaxial fan blades or cooler fan blades by hand. These two

systems are totally independent of each other. The symptoms described

above indicate two separate failures. The art on this page provides an

overview of the systems described above. Refer to this page along with

in-text art while performing troubleshooting.

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