Dealer Service 25
MAN0306 (Rev. 6/16/2006)
Swing Cylinder
Figure 20. Swing Cylinder
Disassemble
On the 2-1/2" spanner nut type cylinders, Figure 20,
unscrew spanner nut (1) using a spanner wrench, or
carefully use a punch and hammer.
Tap rod guide (2) into barrel (3) about 1/2". Remove
round retaining ring (G). Pull on rod (4) to remove parts
from barrel.
Clamp cross pin end of rod assembly (4) in a vise with
protective jaws. Remove cotter pin (5) and nut (6) from
rod assembly. Remove piston (7) and rod guide (2)
from rod.
Remove and discard all seals, wear rings and O-rings.
Clean all components in solvent and blow dry with low
pressure air.
Inspect inside of cylinder barrel and rod surface for any
scratches or scouring. Small scratches can be
removed with fine crocus cloth. If scratches cannot be
repaired, replace entire cylinder.
Assemble
Lubricate O-rings and seals with clean hydraulic fluid.
Install back-up washer (E) on rod guide (2), then install
O-ring (D) in exterior O-ring groove of rod guide. Install
rod seal (F) into inner groove of rod guide with open
portion of V-groove toward piston.
Place rod wiper (H) in outer rod guide groove. Slide rod
guide assembly (5) onto rod (1). Place iron rings (J) in
outer grooves of piston. Place piston seal (A) and O-
ring (B) in center piston groove. Install O-ring (C) on lip
of piston.
Install piston (7) onto rod (4). Install nut (6) and torque
to 150-180 lbs-ft. Install cotter pin (5).
Compress iron ring and piston seal and carefully insert
piston and rod assembly into barrel. Use care to pre-
vent damage while installing.
Carefully push or tap rod guide (2) into barrel (3) just
past groove inside barrel. Insert retaining ring (G) into
groove and pull rod (4) to seat rod guide (2) against
ring. Apply thread-locking compound (removable) to
spanner nut (1). Screw spanner nut (1) onto rod guide
(2) using a spanner wrench, or carefully use a punch
and hammer.
1. Spanner nut
2. Rod guide
3. Barrel
4. Rod assembly
5. Cotter pin
6. Slotted nut
7. Piston
A. Seal
B. O-ring
C. O-ring
D. O-ring
E. Backup ring
F. Rod seal
G. Retaining ring
H. Wiper
J. Iron ring