JLG 4394RT Service Manual - Manual (Page 79)

SECTION 3 - CHASSIS, PLATFORM & SCISSOR ARMS
3121249 – JLG Lift – 3-43
5. Install the drive motor on the hub, then release the
hydraulic pressure at the brake release port. The
coupling will remain in position.
Disconnect the hydraulic power supply and reconnect the
line going into the brake release port.
3.5 DRIVE MOTOR (SAUER)
Description
The drive motors are low to medium power, two-position
axial piston motors incorporating an integral servo piston.
They are designed for operation in both open and closed
circuit applications. The standard control is a direct acting
single line hydraulic control. The integral servo piston con-
trols motor displacement.
The motors are spring biased to maximum displacement
and hydraulically shifted to minimum displacement. Mini-
mum and maximum displacement can be set with fixed
internal stops. The large diameter servo piston allows
smooth acceleration and deceleration with relatively large
circuit orificing.
Shaft Seal Replacement
REMOVAL
1. Remove the snap ring (1) retaining the shaft seal
and support washer.
2. Remove the support washer (2).
3. Carefully pry out the shaft seal (3).
To avoid damaging the shaft during removal, install
a large sheet metal screw into the chuck of a slide
hammer. Drive the screw into the seal surface and
use the slide hammer to pull the seal.
4. Discard the seal.
Bias spring
Servo piston
Swashplate
Output
Shaft
Piston
Slipper
Cylinder
Block
Endcap
Shaft
Seal
Bearing
Minimum
Angle
Stop
Valve plate
Figure 3-9. Drive Motor Cross Section
1
2
3
1. Snap Ring
2. Support Washer
3. Shaft Seal
Figure 3-10. Removing the Shaft Seal