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

Page: 396 / 1024

PIPER CHEROKEE SERVICE MANUAL
VIIA - LANDING GEAR AND BRAKE SYSTEM 01/31/08
(PA-28R)
2H18
c. Loosen the jam nut on the rubber bumper stop and turn in approximately three (3) turns.
NOTE: Some aircraft are equipped with a large 1 l/8” diameter flat rubber stop. If these stops have
washers of any type between the jam nut and the threaded receptacle, remove these
washers and discard.
d. Operate pump to purge system of air and check fluid level in reservoir . Replenish as necessary.
e. Retract landing gear with care, by turning master switch ON, raising the emergency gear extension
lever and moving the gear selector handle to the UP position. Be sure that the actuator piston is
fully retracted (bottomed) before any part of the gear mechanism contacts adjacent parts.
NOTE: If the actuator piston needs adjustment, initially set rod end bearing midway between
witness hole and full engagement and reinstall on downlock hook.
f. Check 5.80” ± 0.12” dimension. (See Figure 7A-4.) Adjust piston rod end to obtain this dimension.
NOTE: Be sure gear retraction is not being limited by rubber bumper. Turn bumper in further if
necessary.
g. With gear retracted and rigged to 5.80” ± 0.12” dimension, turn rubber bumper finger tight against
the upper drag link. Lower gear, extend bumper screw an additional one half turn and tighten jam
nut.
h. With gear down and locked, check to ensure that positive additional actuator rod travel is available
by removing rod end bolt and pulling piston out until it “bottoms.”
i. Check to ensure that rod end threads cover witness hole in the actuator rod.
j. Tighten jam nut on rod end bearing and complete hook-up of piston rod end bearing to downlock
hook.
k. Adjust shimmy dampener by turning nose wheel against stops and adjusting the rod end of the
dampener for adequate travel to both extremes.
l. Install engine cowling, retract and cycle landing gear, including free-fall, and rig nose gear door per
paragraph 7A-18.
m. Verify gear are down and locked and remove the airplane from jacks.
7A-14. ALIGNMENT OF NOSE LANDING GEAR. On 1974 models, the nose wheel steering has been
modified by the addition of the bungee system. This will require some different adjustment procedures
which are included with the regular instructions below.
a. Place the airplane on a smooth level floor that will accommodate the striking of a chalk line.
b. Ascertain that the nose gear is properly adjusted as given in paragraphs 7A-12, 7A-13, or 7A-13a,
above.
c. With the landing gear in the down-locked position, weight proportionally on the nose gear and the
nose wheel facing forward, adjust the steering bellcrank. The bellcrank is attached at the lower front
of the engine mount directly aft of the gear housing and may be adjusted by loosening its
attachment bolt and sliding the bellcrank fore and aft until it clears each steering arm rollers by 0.03
inch. Retighten the attachment bolt.
d. Place the airplane on jacks. (Refer to Jacking, Section II.)
e. Level the airplane laterally and longitudinally. (Refer to Leveling, Section II.)
f. From the center point of the tail skid, extend a plumb bob and mark the contact point on the floor.
g. Extend a chalk line from the mark on the floor below the tail skid to a point approximately three
feet forward of the nose wheel. Allow the line to pass under the wheel at the center line of the tire.
Snap the chalk line.
h. Clamp the rudder pedals to align then in a lateral position. Ascertain that the rudder pedals are in
there neutral position. (Refer to Figure 7A-6 and Table VII-I.)