JLG 450A_AJ Series II Service Manual - Manual (Page 276)

SECTION 4 - BOOM & PLATFORM
4-10 – JLG Lift – 3121180
If actuator is not equipped with grease fittings, coat thrust
bearings (20) with grease before sliding on shaft and end
cap.
Shaft is installed by again aligning punched timing marks.
Temporarily taping threaded portion of shaft will help
installation past shaft seals (masking tape works well).
Apply anti-seize to threaded and surrounding areas of
end caps. NOTE: End caps on 60K and larger actuators may need to
be installed with actuator in a vertical position.
End cap (5) is torqued to 60-400 ft-lb (84-560 Nm)
depending on the actuator size, so actuator begins rota-
tion at approximately 100 psi (6.9 bar) pressure. Shaft
flange cannot be rotated by hand; combined backdrive
efficiency and friction prevent manual rotation. If end cap
is torqued too high, actuator may require as much as 300
psi (20.7 bar) to rotate. If end cap is not torqued high
enough, shaft axial motion and radial backlash will result.
End cap must be secured against shaft by tightening cap
screws (7), or installing axial setscrews, depending on
model. Apply hydraulic pressure and check for breakaway
pressure and shaft axial motion.
To test for leakage, pressurize Port P2 to 3000 psi (206.8
bar). No oil should seep from Port P1 or from around end
cap (5). Repeat test by pressurizing Port P1 and check for
leakage out of Port P2, around shaft flange (2B), and from
ring gear pin welds.