Piper Aircraft Corporation Cherokee 140 PA-28-140, Service Manual

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PIPER CHEROKEE SERVICE MANUAL
01/31/08 V - SURFACE CONTROLS
2C7
5-37. RUDDER TRIM CONTROLS.
5-38. REMOVAL OF RUDDER TRIM CONTROLS. (Refer to Figures 5-15 and 5-16.)
a. Remove the cover (1) from over the trim control assembly by removing attaching screws.
b. Remove the rudder trim knob (2) and the cover attaching screws.
c. Rotate the trim knob to the extreme left (counterclockwise) trim position.
d. Disconnect the housing lug from the arm on the rudder pedal torque tube by removing cotter pin,
nut, washer and bolt (7).
e. Remove the threaded bushing (4) from the aft end of the mounting channel (8) by removing cotter
pin and clevis pin (5). Some mounting channels have two holes in the aft end, note from which hole
in the clevis pin was removed.
f. The mounting channel may be removed by removing the channel attaching screws at the inside of
the channel.
5-39. INSTALLATION OF RUDDER TRIM CONTROLS. (Refer to Figures 5-15.)
Install the rudder trim mechanism and set it at the neutral (no load on spring) position. Perform the
procedure only after all other rudder and nose wheel rigging is complete.
a. Install the trim control mounting channel (8) on the upper side of the floor tunnel. A spacer plate
(14) on some models is installed between the channel and the tunnel. Install the attaching screws (9)
which are secured with anchor nuts.
b. Before attaching the assembly to the mounting channel, ascertain that the clips (11) are installed so
the safety wire (12) will be on top. Also, that the threaded bushing (4) is installed on the assembly
shaft (15) with the welded attachment bushing forward or toward the housing.
c. Attach the housing lug to the arm provided on the rudder pedal torque tube and secure with bolt,
washer and nut (7). Tighten the nut only finger tight and safety with cotter pin.
d. Clamp the rudder pedals in neutral and position the threaded bushing in the mounting channel (8).
Turn the control shaft until the holes in the bushing and channel align and then install the clevis pin
and cotter pin (5). Should two thru holes be located in the aft end of the mounting channel, the pin
must be installed through the hole that will give equal travel and hit rudder stops before bottoming
out of the trim assembly.
e. With the rudder pedals neutral and no pressure fore or aft on the clevis pin, install the assembly
cover (1) so that the indicator washer (13) and the neutral mark on the cover align.
f. Install the trim cover, secure with screws, and install the trim control knob.
5-40. RIGGING AND ADJUSTMENT OF RUDDER TRIM CONTROLS. Perform these procedures only
after all other rudder and nose wheel rigging is complete. No adjustments are necessary other than those
required during installation of the assembly in the airplane as given in paragraph 5-39.
CAUTION: VERIFY FREE AND CORRECT MOVEMENT OF RUDDER. WHILE IT WOULD
SEEM SELF-EVIDENT, FIELD EXPERIENCE HAS SHOWN THAT THIS CHECK IS
FREQUENTLY MISINTERPRETED OR NOT PERFORMED AT ALL. ACCORDINGLY,
UPON COMPLETION OF RUDDER TRIM RIGGING AND ADJUSTMENT, VERIFY
THAT THE RUDDER MOVES LEFT WHEN THE RUDDER TRIM WHEEL IS
TRIMMED LEFT; AND, THAT THE RUDDER MOVES RIGHT WHEN THE RUDDER
TRIM WHEEL IS TRIMMED RIGHT.