FLUID CHANGE PROCEDURE
This transaxle is designed with a serviceable
filter. To ensure constant fluid quality levels and
longer life, an initial oil and filter change at 100
hours is recommended. Subsequent changes
are recommended at 400 hour intervals minimum, or yearly, whichever comes first.
Oil Fill Volume
(Fill to 100% capacity)
The following procedure can be performed with
the transaxle installed in the vehicle, and the
vehicle on level ground. Apply the bypass valve
and lock the vehicle parking brake.
1. Place an oil drain pan (12” or more in diam
ter and 8 qt. capacity is optimal) beneath the
oil filter. Remove the oil filter cover from the
transaxle to drain the oil. Remove the O-ring
from the cover and discard the O-ring.
2. After the oil has drained from the transaxle,
remove the oil filter from the transaxle housing.
3. Install a new filter (Hydro-Gear part number
71943). Install a new O-ring onto the filter
cover and install the filter cover. See Figure
3a. See page 15 for torque specifications.
4. Remove the top oil fill vent port plug (see
page 5) and fill the transaxle with new
20W50 motor oil through the expansion
tank port/fill port until oil reaches the oil fill
vent port.
Oil Volume = 4875 - 4925 mL
(164.8 - 166.5 fl. oz.)
(1.287 - 1.301 gal.)
Figure 3, Oil Volume
Note: The oil volume figure shown does not
include what is in the expansion tank
hose or the expansion tank. That will
have to be determined by the machine
manufacturer/end user due to varying
hose sizes/lengths and expansion tank
sizes.
5. Install the top oil fill vent port plug and continue filling the system with oil until the fill
line is reached in the expansion tank.
6. Drain old oil filter of all free flowing oil prior
to disposal. Place used oil in appropriate
containers and deliver to an approved recycling collection facility.
Filter
7. Proceed to the purge procedure.
O-ring
Filter cover
Figure 3a, Filter Components
10
ZT-5400 Powertrain
PURGING PROCEDURES
Due to the effects air has on efficiency in
hydrostatic drive applications, it is critical that
it be purged from the system.
These purge procedures should be implemented any time a hydrostatic system has
been opened to facilitate maintenance or any
additional oil has been added to the system.
Air creates inefficiency because its compression and expansion rate is higher than that of
the oil approved for use in hydrostatic drive
systems.
The resulting symptoms in hydrostatic systems
may be:
1. Noisy operation.
2. Lack of power or drive after short term
operation.
3. High operation temperature and excessive
expansion of oil.
The following procedures should be performed
with the vehicle drive wheels off the ground,
then repeated under normal operating conditions.
1. With the bypass valve open and the engine
running, slowly move the directional control
in both forward and reverse directions
(5 to 6 times), as air is purged from the unit,
the oil level will drop.
2. With the bypass valve closed and the
engine running, slowly move the directional
control in both forward and reverse
directions (5 to 6 times). Check the oil level,
and add oil as required after stopping
engine.
3. It may be necessary to repeat Steps 1 and 2
until all the air is completely purged from the
system. When the transaxle moves forward
and reverse at normal speed purging is
complete.
Before starting, make sure the transaxle/transmission is at the proper oil level. If it is not, fill
to the specifications outlined on page 9.
ZT-5400 Powertrain
11
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