Lull 6K Service Manual - Manual (Page 277)

Boom and Transfer
Service Manual — Models 644B, 6K, 844C, 8K, 1044C, 10K 6-27
Note: 10K and 1044C models have three (3) holes in the side of the rod bearing
head.
5. Remove the cylinder rod assembly from cylinder barrel.
CAUTION: To prevent possible damage to components, support cylinder
rod assembly; do not wiggle rod or head back and forth during
removal.
6. Remove rod nut (Item 4), piston (Item 5), stroke limiter (Item 6), and
rod bearing head from rod (Item 8).
Note: Some models do not have a stroke limiter (Item 6) This applies to
the following models:
6K-37 (S/N 101–229) 6K-42 (S/N 101–109)
644B-37 (S/N 101–434) 644B-42 (S/N 101–130)
8K-42 (S/N 101–180) 844C-42 (S/N 101–319)
All 10K-42, 10K-54, 1044C-42, and 1044C-54 models
7. Inspect bushings for damage. The following steps are necessary if
bushing(s) need to be replaced:
a. Remove bushing (Item 9) from cylinder rod using a bushing driver
and hammer or press.
b. Install new bushing so that it is centered in rod end opening.
c. To ensure proper lubrication, make sure an adequate amount of
grease is applied to the grease fitting after cylinder is reinstalled on
machine.
8. If necessary, remove grease fitting cover (Item 11) and grease fitting
(Item 10) from cylinder. Inspect and replace if damaged. Install and
tighten fitting 1.5 to 3 turns past finger tight.
9. Remove all O-rings, wear rings, and backup rings from cylinder
components and discard.
10. Thoroughly clean components with solvent and dry with compressed
air.
11. Inspect inner surface of barrel, outer surface of piston, and length of
rod for scratches and scoring. If barrel, piston, or rod is damaged, it
must be replaced.
12. Check condition of threads on rod and rod nut. Do not attempt to repair
damaged threads.
13. Lubricate new O-ring with hydraulic oil and install inside piston (seals
rod to piston).
14. Lubricate new O-ring, backup ring, seals, and wear rings with hydraulic
oil and install on rod bearing head. Using a seal driver, install new
wiper seal in head. Lubricate wiper seal with hydraulic oil.
15. Slide rod bearing head (Item 7), stroke limiter (Item 6) (see note after
Step 6), and piston (Item 5) onto rod (Item 8). Lubricate threads on rod
with hydraulic oil and install rod nut (Item 4). Torque rod nut as follows: