PROCEDURE 4: CORRECTING SHAFT BALANCE
a. After the measurement is completed, press DO on Finish, then press DO on Diagnostics. If measurements are
within specified limits, press QUIT to Main Menu. Proceed to step d.
b. If measured values exceed manufacturer's desired levels on engine 2, press the DO key to enter the DIAGS
mode. Perform all corrections displayed on the Corrections screen. If alterations of these corrective actions
are desired, use the EDIT ADJUSTABLES option and turn off adjustment not wanted. Do not use a partial set
of the adjustments.
c. After No. 2 engine corrections are installed or recorded, press QUIT two times to return to Main Menu.
d. Use cursor keys to highlight Flight Plan. Press DO.
e. Use cursor keys to highlight ENG1. Press DO.
Use cursor keys to highlight Flight ID. Press DO two times.
g. Run diagnostics on No. 1 engine by pressing F3. If measurements are within specified limits, press QUIT to
h. If measured values exceed manufacturer's desired levels, press the DO key to enter the DIAGS mode.
Perform all corrections displayed on the Corrections screen. If alterations of these corrective actions are
desired, use the EDIT ADJUSTABLES option and turn off adjustments not wanted. Do not use a partial set of
Repeat test to verify that vibration levels are within specifications.
Return to a flight-ready condition.
When balancing an aircraft with the balance bolt
configuration, the following guidelines must be observed
when installing balance washers:
AN960-416 and AN960-416L washers are used
as balance washers.
Balance washers are installed under the nut on
the bolts that connect the engine output shaft to
the flexible coupling. See figure 22.
The maximum number of balance washers that
can be added to any one balance bolt is two.
Do not remove bolts securing flexible coupling to
output shaft. If balance washers must be added,
remove nut only.
Only one nut should be removed at any time. If
balance washers are added or removed on two
different balance bolts, the nut on the first
balance bolt adjusted must be installed and
torqued before removing next nut.
Balance bolts are subject to the same torque
stabilization procedures as the balance studs.
Refer to TM 1-1520-237-23 for the proper torque