JLG 680S, Service And Maintenance Manual

Page: 122 / 530

SECTION 3 - CHASSIS & TURNTABLE
3-70 3121234
12. Press the rear shaft bearing (22) into the end cap. Install
the bearing with letters facing out. Press until bearing
surface is 0.08 ±0.01 in. (2 ±0.25 mm) above end cap sur-
face.
13. Install timing pin (23) into its bore in the end cap. Install
the pin with its groove facing toward or away from the
shaft. Press the pin until the end protrudes 0.12 ±0.01 in.
(3 ±0.25 mm) above end cap surface.
14. Install the valve plate (24) onto the end cap. Install the
valve plate with the yellow surface toward the cylinder
block. Align the slot in the valve plate with the timing
pin. Apply a liberal coat of assembly grease to the end
cap side of the valve plate to keep it in place during
installation.
15. Install the end cap (25) onto the housing with the end
capscrews (26). Check to ensure the end cap will prop-
erly seat onto the housing without interference.
Improper assembly of the internal components may
prevent the end cap from seating properly. Ensure the o-
rings seat properly when installing the end cap.
16. Using an 8 mm internal hex wrench, tighten the end
capscrews. Tighten the screws in opposite corners
slowly and evenly to compress the servo spring and
properly seat the end cap. Torque end capscrews
35-45 ft. lbs. (47-61 Nm).
17. Before installing the shaft seal, ensure the shaft turns
smoothly with less than 120 in. lbs. (13.5 Nm) of force. If
the shaft does not turn smoothly within the specified
maximum force, disassemble and check the unit.
23
23
22
24
3 mm
[0.12 in]
2 mm
[0.08 in]
23
22
22. Rear Shaft Bearing
23. Timing Pin
24. Valve Plate
Figure 3-54. Valve Plate and Rear Bearing
26
25
8 mm
(47-61 Nm)
35-45 ft.lbs.
25. End Cap
26. Screw
Figure 3-55. End Cap