87637, 87638 and 87658 Electric Jack Upper Assembly Replacement – Rev. 2011-06-16
Step 12:
Align the upper jack assembly with the lower jack
assembly laying on a bench together as shown in Figure K.
The front hole of the outer tube, circled in Figure L, needs to
be facing the same direction as the motor on the upper jack
assembly. The front hole is the one opposite the
“Max.
Cap.
” stamp on the mounting plate. This is the position you
must maintain when you slide the two together in step 15.
Step 13:
Screw the ball screw back into the lower jack
assembly 1½ turns. This sets the
Smart Stop™ fully
extended position a safe distance from the end stop on the
ball screw.
Step 14:
Align the pin hole in the end of the ball screw with the pin hole of the drive
adapter and put the end of the ball screw into the drive adapter hole in the upper jack
assembly (Figure M). You may have to rotate the ball screw
⅛
-
¼
turn in or out to
accomplish this but that will not affect the Smart Stop
™ performance. Put the upper
ball screw pin through the holes of the drive adapter and ball screw and install the
cotter pin removed in step 5. (Figure N).
Step 15:
Maintaining the position set in step 12, slide the outer tube up to base of the
upper jack assembly. Install the outer tube to the base of upper assembly using the
four Allen head cap screws and lock washers from step 4 and a 6mm Allen wrench or
socket. Using a torque wrench, tighten the bolts to a torque of approximately 15-20
ft-lbs. If you do not have a torque wrench, the bolt torque can be calculated by
multiplying the force you exert in pounds on your wrench or ratchet
(“F” in Figure O),
by the distance from the center of the bolt to the center of your hand in feet
(“D” in
Figure O). To calculate the force you must exert on your wrench or ratchet, divide
the required bolt torque (15-20ft-lbs) by
the distance “D”; shown in Figure O. If “D” is
1ft
then the force “F” needs to be 15-20lbs. If “D” is 2ft then the force “F” needs to be
7.5-
10lbs. If “D” is 0.5ft (6”) then the force “F” needs to be 30-40lbs.
Step 16:
Connect the power wire from the new upper jack assembly to the positive
terminal of your battery. Connect your negative battery terminal to the body of the
jack using one of the top cover screws (Figure G) or a suitable alligator clip (Figure
H).
Step 17:
Activate the jack switch in the “DOWN” position and hold it there until the
Smart Stop automatically stops the power to the motor. The jack should be fully
retracted and the
Smart Stop™ should have cut power to the motor before it stalled
against the upper ball screw stop. Activate the jack switch in the “UP” position and
hold it there until the
Smart Stop™ automatically stops the power to the motor. The
jack should be fully extended and the
Smart Stop™ should have cut power to the
motor before it stalled against the lower ball screw stop. Activate the jack switch in
the “DOWN” position again and fully retract the jack. It is now ready for installation
on your trailer. If the Smart Stop fails to cut the power to the motor before it stalls
against the ball screw end stops in either direction then let go of the switch
immediately. Repeat the installation procedure from step 4 to ensure that the ball
screw was synchronized with the
Smart Stop™ correctly in steps 8-15. You can skip
step 6 and step 9 if repeating the procedure.
Step 18:
If your Smar
t Stop™ is functioning as required in step 17, then re-assemble
the plastic covers on the upper jack assembly and ensure the motor cover and lower
rear cover engage the groove of the rubber outer tube seal. Your jack is now ready
to install on your trailer.
Figure M
Figure N
Figure O
D
F
Figure L
Figure K
