Drive Motor - 2Wd (Sn 0300087000 Through 0300098765); Shaft Seal Replacement; Drive Motor; Description - JLG 600A Service And Maintenance Manual

SECTION 3 - CHASSIS & TURNTABLE
3.9 DRIVE MOTOR - 2WD (SN 0300087000
THROUGH 0300098765)

Shaft Seal Replacement

Lip type shaft seals are used an the drive motors. These seals
can be replaced without major disassembly of the unit. How-
ever, replacement of the shaft seal requires removal of the
pump or motor from the machine.
1. Remove the retaining ring from the housing.
Carefully remove the seal from the housing bore. The face of
the seal may be punctured with a sharp instrument (such as a
screw driver) to aid in prying the seal out, or a slide hammer
type puller may be used to remove the seal. Care must be
taken not to damage the housing bore or shaft. Once removed
the seal is not reusable.
Prior to installing the new seal, inspect the sealing area on the
shaft for rust, wear, or contamination. Polish the sealing area
on the shaft if necessary.
Wrap the spline or key end of shaft with thin plastic to prevent
damage to the seal lip during installation. Lubricate the inside
diameter of the new seal with petroleum jelly.
NOTE: The outside diameter of the seal may be lightly coated with
a sealant (such as Loctite High Performance Sealant
#59231) prior to installation This will aid in preventing
leaks caused by damage to the housing seal bore.
Slide the new seal over the shaft and press it into the housing
bore. Be careful not to damage seal. A seal installer tool can be
made to aid in installing the seal.
Reinstall the seal retaining ring.
3-38
3.10 DRIVE MOTOR (USA BUILT MACHINE AND CHINA
BUILT MACHINE, SN 0300098766 TO PRESENT
AND SN B300000100 TO PRESENT)

Description

1. The drive motors are low to medium power, two-posi-
tion 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 controls motor displacement.
2. The motors are spring biased to maximum displacement
and hydraulically shifted to minimum displacement.
Minimum 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.
Bias spring
Minimum
Angle
Stop
Cylinder
Block
Piston
Endcap
Valve plate
Figure 3-23. Drive Motor Cross Section
Servo piston
Swashplate
Output
Shaft
Shaft
Seal
Bearing
Slipper
3121201