Lull 944E-42, Service Manual

Page: 421 / 844

8.171 Model 644E-42/944E-42 Rev. 6/04
Hydraulic System
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 secondary 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 primary 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 secondary section cover (12). Be
sure the plastic seal retainer (14) is facing away from
the primary 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 primary section cover.
16. Line up the alignment notches or the alignment
marks and install the secondary section cover (12)
onto the rear center section (9). It may be necessary
to use a plastic mallet to seat the secondary section
cover onto 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 primary
section cover. Seat the primary section cover tightly
against the front center section.
17. Secure the secondary 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).