Appendix B: Manual Servo Control Basic Assembly - Eaton 72400 Repair Information

Model 72400
Appendix B -
Manual Servo Control Basic Assembly
Disassembly -
Manual Servo Control Assembly
1 Remove wiper seal with screw driver. Remove set screw
retaining input shaft and remove input shaft from control
housing.
2 Remove set screw from plug retaining valve spool and
remove plug.
3 Remove E-ring from pin retaining feedback link and valve
spool. Remove pin, feedback link, valve spool, and bell crank
from control housing.
4 Compress spring and remove E-ring, spring retainer,
spring, and second spring retainer from valve spool.
5 Remove o-rings from plug and input shaft. Clean all parts
and lubricate in prep for reassembly.
Reassembly -
Manual Servo Control Assembly
1 Install spring retainer, spring, and second spring retainer
onto spool. Compress spring with retainer and retain with E-
ring onto valve spool.
2 Install valve spool into control housing making sure that
metering notches on valve spool can be seen in the metering
ports. Notches shown in figure 2-1.
3 Position bell crank in housing. Slide feedback link into
position between clevis on valve spool, aligning holes, and
install dowel pin retaining with E-ring.
4 Install new o-ring onto input shaft. Hold bell crank in
position with feedback link slot and align splined hole of bell
crank with input shaft cavity. Install input shaft into control
housing and bell crank.
5 Apply Loctite #242 or equivilent to set screw and install,
retaining input shaft. Adjust set screw until it bottoms out on
input shaft and back out one-quarter turn.
6 Install wiper seal on input shaft as shown in figure 2-2.
7 Install new o-ring onto plug, retaining valve spool, and
install plug. Adjust plug until there is no play in the valve spool
with input shaft held stationary. Lock in place with set screw.
Torque set screw 2 to 3 N•m [17 to 25 lbf•in].
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