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Section 7: Retract Servo Installation
Required Parts
• 4-40 x 10-1/2" threaded rod (2)
• Right and left wing panels
• Retract servo with hardware (2) (JRPS703)
• Easy connector (2)
• Connector back plate (2)
• 4-40 x 1/4" screw (2) • Metal clevis (2)
• Clevis keeper (2)
• 4-40 nut (2)
Required Tools and Adhesives
• Threadlocking compound
• Drill Bit: 1/16", 7/64" • Drill
• Phillips screwdriver
• 3/32" hex wrench
• Hobby knife
• Side cutters
• Felt-tipped pen
Note
: The retract mechanism for the P-51
comes preinstalled from Hangar 9
®
. The P-51
retract system is designed to use low-profile
retract servos, such as the JRPS703.
Step 1
Remove the retract from the wing by removing the four
#2 x 3/8" screws that hold the retract in position.
Step 2
Prepare the retract linkage by threading a 4-40nut onto
the shaft. Slide a clevis keeper onto the metal clevis, then
thread the clevis onto the 4-40 x 10
1
/
2
" threaded rod.
The threads of the threaded rod should be visible between
the forks of the clevis.
Step 3
Connect the clevis to the retract actuator lever. Slide
the clevis keeper onto the clevis to prevent the clevis
from opening up during flight. Apply a small amount of
threadlocking compound behind the clevis, then tighten
the nut against the clevis. This will prevent the threaded
rod from rotating in the clevis, which could lead to
failure in flight.
Step 4
Cut the threaded rod to a length of 9
1
/
2
”. Make a slight
bend as shown in the photo to make the installation of the
retract in the next step easier.
Photo for Step 5
