Lull 6K Service Manual - Manual (Page 531)

Frame Tilt and Oscillation
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 7-29
Disassembly, Rear Oscillation Lock Cylinder
(Ref. Fig. 7-18) Disassembly procedures for the rear oscillation lock
cylinder are as follows:
1. Mount or support cylinder vertically, with rod end down. Hydraulic oil in
cylinder will drain out during disassembly. Place a suitable pan or tray
under cylinder.
2. See warning and procedures on page 7-34 for removal of oscillation
control block.
3. Slowly extend and retract cylinder by hand to remove most of the
hydraulic oil.
4. Remove eight (8) capscrews (Item 7) securing head (Item 8) to barrel
(Item 2).
5. Pull rod (Item 6) out to help remove head. Support rod and head
during removal to prevent damage. Do not wiggle the rod or head back
and forth to remove; this may damage the components.
6. Remove rod nut (Item 3), piston (Item 4), stroke limiter (Item 5), and
head from rod.
7. If the bushings need to be replaced, see “Bushing Replacement, Rear
Oscillation Lock Cylinder” below.
Cleaning and Inspection, Rear Oscillation Lock Cylinder
1. Remove all O-rings, wear rings, and backup rings from cylinder
components and discard.
2. Thoroughly wash components in solvent and dry with compressed air.
3. Inspect inner surface of barrel, the outer surface of piston, and rod for
scratches and scoring. If barrel, piston, or rod is damaged, the
component must be replaced.
4. Check condition of threads on rod, nut, and capscrews. Replace as
necessary. Do not attempt to repair damaged threads.
Bushing Replacement, Rear Oscillation Lock Cylinder
1. Fig. 7-18 shows both types of rod end configurations and bushing
locations. Remove pivot bushings (Item 1) using a bushing driver and
hammer or press. Drive one bushing all the way through to remove
other bushing.
2. Install new bushings so they are flush with outer edge of boss to 0.02"
below. For machines with lower (rod end) pivot bushing installed in rear
axle: Install bushing so that it is centered in axle boss.