Piper Navajo PA-31 Service Manual page 89

PIPER NAVAJO SERVICE MANUAL
2. Hold the spline end of the flexible shaft securely with one hand and gently turn the flap motor
to remove rotational play in the splines. Place a reference mark on the motor housing adjacent to the wire
pointer. Turn the flap motor gently in the opposite direction to remove rotational play and place another
reference mark on the motor housing. If any distance between these two marks exceed 5 32 of an inch (4mm)
replace the flexible shaft assembly
1. While holding the transmission end of the drive shaft stationary twist the motor end one turn
clockwise and release. Inspect for evidence of movement between the inner cable and the swaged fittings at
both ends. Turn cable one turn counterclockwise and repeat inspection. If movement or separation between
the inner cable and the swage fitting is apparent. replace the flexible shaft assembly.
NOTE
If pliers or similar tool is used to twist cable, wrap cable ends with
tape or cloth to prevent damage.
J. Determine that the inner cable moves freely within the housing and may be turned easily by hand.
If there is any snagging or binding the cable must be replaced.
k. Ascertain that the flap motor shaft is centered within the motor adapter housing. ( Refer to Figure
3-2a.. View C).
1. Install the flap actuator motor and bracket on the forward side of the bulkhead at fuselage station
174.0. Ensure that the anti-rotation pin on the motor fits in the pin hole in the mounting bracket. Secure the
holding clamp
m. Lubricate both ends of the flexible shafts with MIL-G-23827 grease.
n. Check flap rigging and adjustments as outlined in Section V. Surface Controls.
o. Reinstall floorboards and access panels.
S 764A
3-10. REDUCTION OF FRICTION IN WING FLAP SYSTEM. (Dukes System)(Referto Figure3-3.)To
insure proper flap system operation and reduce friction on the flap motor. the following inspection and repairs
are only required should operational problems exist in the flap system:
a. Remove both right and left flap assemblies from the aircraft. (Refer to Section IV
b. Clean all paint and dirt from the top and bottom of the flap tracks.
c. Inspect the flap tracks for any burrs along the track edges. If any are found. remo e them with a fine
file. Insure that no noticeable depressions are evident at the ends of the track areas. (Refer to Figure 3-3 for
specific locations.)
d. Using fine sandpaper. polish the inside surfaces of the flap tracks and lubricate the tracks with light
oil. MIL-L-7870 or Dupont Slip Spray No. 6611.
e. Clean all dirt and paint from the flap rollers.
f. On each flap roller. remo e .015 or .016 of an inch from one side of each roller (Refer to Figure 3-3.
View A-A.)
g. Polish all flap rollers and lubricate with light oil. MIL-L-7870.
h. Insure that the washers. used on both sides of the rollers are flat. (Refer to Figure 3-3. View A-A)
i.
Install both flap assemblies on the aircraft. (Refer to Section IV ) Do not connect the flap
transmission screws to the flaps at this time.
j. Ascertain that the flap rollers turn freely and that the flaps will move freely in the flap tracks under
their own weight through the entire length of the flap tracks.
k. Insure that the flap transmission screw fits into the horn assembly on the flap without any binding.
throughout the flap travel.
NOTE
It may be necessary to move the horn assembly to obtain this no
binding fit. The mounting holes on the horn assembly may be slotted
to gain some adjustment if needed. (Refer to Figure 3-3. View B-B
for dimensions of slots.)
Revised: 11/15/82
INSPECTION
1D17