User's Manual
Service
Hydraulic Motor Disassembly
NOTE:
Repair Kit 236–698 is available. For the best
results, use all the parts in the kit. Kit parts are marked
with an asterisk, for example (2*).
NOTE:
When disassembling, lay out all parts in
sequence, to make reassembly easier
. Clean and
inspect all parts for wear or damage before
reassembling. Replace as necessary
.
1.
Remove the hydraulic motor from the pump as
explained in the separate system manual. Lay it on
its side in a pan.
2.
Unthread the tie rods (37) from the retainer (36)
and the tie plate, and pull them out through the
top of the hydraulic motor
. It will be necessary to
remove the lower four nuts (27) and lockwashers
(28).
3.
Unscrew the four fluid tube nuts (N) and remove
the tubes (32, 39). See Fig. 1. Allow excess oil to
drain from the hydraulic motor
, then plug the fluid
fittings.
CAUTION
Keep the hydraulic system clean
Always plug the hydraulic inlets, outlets and lines
when disconnecting them for any reason to avoid
introducing dirt and other contaminants into the
system.
4.
Pull the top valve spool (1), cylinder (33), and
displacement rod (9) together of
f the bottom
cylinder cap (35). Remove the o-ring (2) from the
bottom cap.
5.
Grasp the valve spool(1) and pull the cylinder (33)
of
f. Slide the cylinder of
f the displacement rod (9).
Be careful not to damage the rod. Remove the
o-ring (2) from the valve spool.
6.
Lay the valve spool (1) and displacement rod (9)
on a table. Place a clean rag around the yoke (4)
to prevent the detent balls (3) from popping out.
Push the yoke (4) sideways of
f the valve sleeve
(19) while holding the balls (3) and spring (18) with
the rag, then carefully remove the balls and spring.
7.
Inspect the valve sleeve (19), valve stop (25), and
spool (S) for damage. See Fig. 2. If any of these
parts requires replacement, unscrew the two
screws (26) holding the stop (25) to the spool (S).
Remove the stop and slide the sleeve (19) of
f the
spool. If the spool is damaged, replace the valve
spool (1).
NOTE:
If any of these parts are being reused,
thoroughly clean any adhesive residue from the screws
and female threads of the spool. Use a surface cleaner
such as chlorinated solvent on the threads and blow
dry with compressed air
. If necessary, use a 10–24
unc–2b tap to remove adhesive from the female
threads.
8.
Remove the capscrew (23), sealing washer (22)
and o-ring (24) from the cap plate (29). Lift of
f the
cap plate and remove the o-ring (20).
9.
Hold the flats of the displacement rod (9) in a vise
and use a spanner wrench in the pin holes of the
piston (16) to screw it of
f the rod. Remove the trip
rod (17) from the displacement rod.
CAUTION
Be careful not to scratch the outside of the displace
-
ment rod.
10.
Unscrew the nut (48) and remove the retainers
(11) and spring (12) from the trip rod (17).
11.
Slide the piston (16) of
f the trip rod (17). Remove
the bearing (5), seal (6), and o-rings (7 and 8) from
the piston.
12.
Inspect the yoke (4) and trip rod (17) for damage.
If either part requires replacement, slide the yoke
into Repair T
ool 189–305 and set the tool in a vise.
See Fig. 2. Use a wrench on the flats of the trip
rod and unscrew the rod from the yoke.
13.
Pull the housing retainer (36) away from the
bottom cylinder cap (35).
14.
Remove the block packings (14 and 49), wiper
(15), bearing (13), and o-ring (2) from the housing
retainer and bottom cylinder cap.