Komatsu 930E-2 Shop Manual page 443

Driveshaft Group
NOTE: Be sure punch marks on cylinder bearing (26,
Figure 6-14) will face toward shaft end of pump.
10. Insert cylinder bearing (26) straight into pump
housing. Be sure bearing is positioned so bearing
retainer pins (14, Figure 6-13) can be inserted in
the case and into the bearing.
11. Install O-rings (18) on pins (17) and install pins.
12. An arbor press is required to install shaft bearing
(2, Figure 6-13) onto driveshaft (1). IMPORTANT
- press ONLY on the inner race of the bearing.
Press bearing until it contacts the shoulder on
driveshaft.
13. Use a long 6 in (153 mm) sleeve with an I.D. slightly
larger than the retaining ring I.D. and press retain-
ing ring (4) towards bearing until it seats in the
groove.
14. Place seal retainer (22) over seal (26) inside the
pump housing (21). Lubricate shaft seal with clean
hydraulic oil.
15. Install entire driveshaft assembly through front of
pump housing. A mallet will be required to install
the driveshaft through shaft seal.
16. Once the driveshaft assembly is fully seated in the
pump housing, install snap ring (3).
Rotating Group
17. Mating surfaces should be greased. Place cylinder
assembly on clean table with the valve plate side
down.
18. During disassembly, shoe retainer springs were
referenced to individual bores. Assemble rotating
group by inserting shoe retainer springs (28, Fig-
ure 6-14) into the same spring bores located in
cylinder barrel (10) that they came from.
19. Slide fulcrum ball (12) over the nose of the cylinder
barrel (10).
20. Place shoe retainer (27) over fulcrum ball and align
holes in retainer with corresponding holes
(marked during disassembly) in the cylinder bar-
rel. Once aligned, insert piston/shoe assemblies
(13) into corresponding (marked during disassem-
bly) holes completing the rotating group.
L06021
The assembled rotating group weighs approxi-
mately (30 lbs.). Assistance from others and use
of proper lifting techniques is strongly recom-
mended to prevent personal injury.
21. The rotating group can now be carefully installed
over the end of the driveshaft and into the pump
housing.
22. When installing the rotating group, support the
weight of the cylinder barrel (10, Figure 6-14) as
cylinder spline is passed over the end of driveshaft
to avoid scratching or damage.
23. Push cylinder barrel forward until the cylinder
spline reaches the driveshaft spline. Rotate the
cylinder slightly to engage shaft splines.
24. Continue to slide cylinder barrel forward until it
encounters the cylinder bearing (26). Lifting the
driveshaft slightly helps cylinder barrel and cylin-
der bearing engagement. Continue pushing cylin-
der forward until the piston shoes contact
swashblock (25).
25. At this point, the back of the cylinder barrel should
be located approximately 0.25 in (6.3 mm) inside
the back of the pump housing.
Control Piston Group
26. Install seal and piston ring (2 & 3, Figure 6-14) into
their respective grooves on control piston (11)
using care to assure they are in proper location.
27. Insert control piston assembly into sleeve (4).
28. While supporting the control piston, press or slip
in pin (8) and secure with cotter or roll pin (18).
29. Order of piston sleeve seal installation starts at
widest end of sleeve.
30. Install backup ring (1, Figure 6-18) and O-ring (2)
and back-up ring (3) in rear most groove on piston
sleeve. Install O-ring (4) and back-up ring (5) in
remaining groove.
31. Insert piston and sleeve assembly into valve plate
(11, Figure 6-15). Install O-ring (6) with back-up
ring (5) in seal groove of control cover cap (4).
Steering Circuit Component Repair L6-21