JLG sky trak mmv Service Manual page 391

8. Lubricate the drive gear (7) with clean hydraulic oil.
Very carefully insert the shaft through the wear plate
(5).
9. Lubricate the driven gear (8) with clean hydraulic oil
and install the gear through the wear plate (5) and
into the ported section (2). Align the marks on the
gear teeth and push all the way into the ported
section.
10. Line up the alignment notches or the alignment
marks and install the rear center section (9) onto the
ported section (2). It may be necessary to use a
plastic mallet to seat the front center section on to
the ported section because of the tight fit of the
dowel pins (10). Hold the bronze wear plate (5) in
position while tapping the front center section. Seat
the front center section tightly against the ported
section.
11. Apply a light coating of graphite grease to the new
square cross section o-ring (11) and carefully install
into the groove in the rear section cover (12). Be
careful that the o-ring does not twist in the groove.
The o-ring must be flat in the groove for proper
sealing of the pump when assembled.
12. Coat both the new seal gland (13) and new plastic
seal retainer (14) with graphite grease. Carefully
install the seal gland in the groove in the seal
retainer, make sure the seal gland is seated
completely in the seal retainer.
13. Coat the seal cavity area in the front section cover
with graphite grease to hold the new seals in place
during assembly.
14. Install the assembled seal gland and seal retainer in
the cavity in the rear section cover (12). Be sure the
plastic seal retainer (14) is facing away from the front
section cover. Very carefully press this assembly in
place until it is firmly seated in the machined recess.
This assembly must be seated completely in the
recess to allow proper installation of the bronze wear
plate (15).
15. Lubricate the steel side of the bronze wear plate (15)
with graphite grease and install over the seal retainer
and seal gland assembly. When properly installed
the bronze face will be next to the gears and flush
with the surface of the front section cover.
Model MMV Rev. 12/04
16. Line up the alignment notches or the alignment
marks and install the rear section cover (12) onto the
rear center section (9). It may be necessary to use a
plastic mallet to seat the rear section cover on to the
rear center section because of the tight fit of the
dowel pins (10). Hold the bronze wear plate (15) in
position while tapping the front section cover. Seat
the front section cover tightly against the front center
section.
17. Secure the rear section cover (12) and rear center
section (9) to the ported section (2). Insert the four
long bolts (16) with lockwashers (17) into the four
holes in the raised part of the cover. Insert the four
short bolts (18) with lockwashers (17) into the four
holes in the lower part of the cover. Torque all eight
bolts to 65-75 lb/ft (88-101 Nm).
18. Install the new inner shaft seal (19) into the mounting
flange housing (20), make sure the spring loaded
member of the shaft seal is toward the inside of the
pump. Press the seal into the bore seal bore until the
seal reaches the bottom of the bore. Uniform
pressure must be used to prevent misalignment or
damage to the seal.
19. Retain the inner shaft seal (19) in place with the new
internal retaining ring (21). Be sure the retaining ring
is seated completely in the groove.
20. Install the new outer shaft seal (22) which has a
larger outside diameter into the seal cavity in the
mounting flange housing (20). Make sure the spring
loaded member of the outer shaft seal is toward the
inside of the pump. Uniform pressure must be used
to prevent misalignment or damage to the seal.
Press the seal into the cavity until the seal is seated
properly.
21. Install the eight threaded studs (23) into the ported
section (2). The course thread end of the studs goes
into the ported section. Torque the studs to 25-35
lb/ft (34-47 Nm).
Hydraulic System
9.93