(a)  
Set the STAB TRIM 3 switch on the control stand to CUTOUT and set the STAB TRIM 2 switch to ON.

 (b)  
Operate the STAB TRIM ALTN switches on the control stand to APL NOSE UP and then to APL NOSE DN. 1) Make sure the stabilizer starts smoothly in 1 second. 2) Make sure the stabilizer stops and moves smoothly to the

 opposite direction in 1 second when you change the selection.
 NOTE: The click you hear at the stabilizer trim drive unit
____ is the result of the primary brake ratchet. 3) Make sure the antirotation cables stay loose during the operation. 4) Make sure the stabilizers move to the nose up travel limit from the nose down travel limit in 40-70 seconds.
 (c)  
Set the STAB TRIM 2 switch to CUTOUT and the STAB TRIM 3 switch to ON.

 (d)  
Operate the STAB TRIM ALTN switches to APL NOSE UP and then to APL NOSE DN. 1) Make sure the stabilizer starts smoothly in 1 second. 2) Make sure the stabilizer stops and moves smoothly to the

 opposite direction in 1 second when you change the selection.
 NOTE: The clicking you hear at the stabilizer trim drive unit is the result of the primary brake ratchet. 3) Make sure the antirotation cables stay loose during the operation. 4) Make sure the stabilizers move to the nose up travel limit from the nose down travel limit in 40-70 seconds.
 S 795-011
 (6)  Examine the mechanism for oil leaks.
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747-400 MAINTENANCE MANUAL
 (7)  S 865-012Set the STAB TRIM 2 and 3 switches to ON.
 (8)  S 865-013Use the STAB TRIM ALTN switches to set the stabilizer to the neutral rig position (3 units of trim).
 (9)  S 865-014If the hydraulic power is not necessary, do this task: Hydraulic Power" (Ref 29-11-00/201). "Remove
 S 865-015

 (10)
 If the electrical power is not necessary, do this task:  "Remove Electrical Power" (Ref 24-22-00/201).

 S 415-016

 (11)
 Close the access door 312A (Ref 06-09-05/201).

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747-400 MAINTENANCE MANUAL
 STABILIZER TRIM DRIVE MECHANISM - INSPECTION/CHECK
__________________________________________________
 1.  General_______
 A.  This procedure has four tasks. The first task is an inspection of the stabilizer trim actuator ballnut. The second task is an inspection of the stabilizer trim drive mechanism (which is referred to as the mechanism). The third task is a corrosion inspection of the horizontal stabilizer upper and lower gimbal pin (which is referred to as the gimbal pin). The forth task is a visual inspection of the mechanism. The procedure has these parts:
 (1)  
An inspection of the stabilizer trim actuator ballnut

 (2)  
An inspection of the mechanism:

 (a)  
An inspection of the ballnut to ballscrew

 (b)  
An inspection of the primary brake backlash

 (c)  
An inspection of the gimbal bushing.

 (3)  
A corrosion inspection of the gimbal pin:

 (a)  
The removal of the gimbal pin

 (b)  
An inspection of the gimbal pin for corrosion

 (c)  
The installation of the replacement gimbal pin

 (4)  
A visual inspection of the mechanism.

 TASK 27-41-06-206-013
 2.  Stabilizer Trim Actuator Ballnut Wear Limits Inspection_______________________________________________________
 A.  Special Tools and Equipment
 (1)  
OHME65B80713-1, Horizontal Stabilizer Actuator Handling Equipment (which is referred to as the "handling tool") which includes these parts:

 (a)  
　
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