S 226-042
 (7)  
Examine the longitudinal backlash between the ball screw nut and the ball screw:

 (a)  
Install the dial indicator on the ball screw.

 (b)  
Put the pointer on the dial indicator against the ball screw nut.

 (c)  
Apply a minimum of 50 pounds (23 kilograms) force in the axial direction to the end of the nut. Use a spring scale to measure the force.

 (d)  
Zero the dial indicator while applying the force.

 (e)  
Apply a minimum of 50 pounds (23 kilograms) force in the opposite direction to the end of the nut. Use the scale to measure the force.

 CAUTION:_______REMOVE THE FLAP LOCK TOOLS BEFORE YOU MOVE THE FLAPS. IF YOU DO NOT REMOVE THE FLAP LOCK TOOLS BEFORE YOU READJUST THE FLAPS, YOU CAN CAUSE DAMAGE TO THE FLAPS AND THE FLAP DRIVE MECHANISM.
 (f)  Use the dial indicator to measure the backlash between the ball screw nut and the ball screw.
 NOTE: The dimension will not be correct if you permit the nut
____
 to turn during the check.

 1) Measure the backlash with the ball screw nut in the flaps up position. 2) Measure the backlash with the ball screw nut in the 25-unit position. 3) Measure the backlash with the nut in several positions between the up and the 25-unit positions. 4) Make sure the backlash dimensions are in the tolerance shown on Fig. 601.
 (g)  Remove the dial indicator.
 S 436-043
 (8)  Do this task to connect the gimbal: "Ball Screw Installation" (Ref 27-51-41/401).
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A
747-400 MAINTENANCE MANUAL
 S 096-044
 (9)  
Remove the ball and screw support tool and the flap lock.

 S 416-045

 (10)
 Do the applicable task:  "Inboard Flap Track Fairing Installation" (Ref 27-51-26/401) or "Outboard Flap Track Fairing Installation" (Ref 27-51-31/401).

 G.
Put the Airplane Back to Its Usual Condition

 S 866-046
 (1)  
Do this task to pressurize hydraulic systems No. 1 and 4:
 "Pressurize Hydraulic Systems" (Ref 29-11-00/201).

 S 866-047

 (2)  
Remove the DO-NOT-MOVE tag and put the flap control lever to the UP detent to retract the trailing edge flaps.

 S 866-048

 (3)  
Do this task to depressurize hydraulic systems No. 1 and 4: "Depressurize Hydraulic Systems" (Ref 29-11-00/201).

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A
747-400 MAINTENANCE MANUAL
 NO-COAST DRAG BRAKE - REMOVAL/INSTALLATION
_________________________________________
 1.  General_______
 A.  There are two tasks in this procedure. There is a task for the removal and a task for the installation of the no-coast drag brake on the inboard flaps.
 (1)  
The removal procedure has these parts:

 (a)  
The extension of the flaps

 (b)  
The installation of the door locks on the landing gear doors

 (c)  
The installation of the carriage lock

 (d)  
The removal of the drag brake.

 (2)  
The installation procedure has these parts:

 (a)  
The installation of the drag brake

 (b)  
The removal of the carriage lock

 (c)  
The removal of the door locks on the landing gear doors

 (d)  
The retraction of the flaps.

 TASK 27-51-42-004-001
 2.  No-Coast Drag Brake Removal (Recommended Procedure)___________________________________________________
 A.  Special Tools and Equipment
 (1)  
24ME65B00116, Lock, Inboard TE Flap (4 necessary)

 B.  
References

 (1)  
AMM 24-22-00/201, Manual Control
　
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