Hydro-Gear 310 1500, 310 1700 Hydrostatic Transaxle Service and Repair Manual

Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
310-1500/310-1700
Integrated Hydrostatic Transaxle
Service and Repair Manual
BLN-52178
December 2008
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
TABLE OF CONTENTS
Section
Page
Foreword .............................................................................................................................. 1
Description and Operation ................................................................................................. 2
Introduction.......................................................................................................................... 2
General Description ..................................................................................................................................... 2
Introduction .................................................................................................................................................. 2
Hydraulic Schematic ................................................................................................................................. 3-5
Product Identification ................................................................................................................................... 6
Technical Specifications ............................................................................................................................... 7
Safety .................................................................................................................................... 8
Personal Safety ............................................................................................................................................ 8
Tool Safety ................................................................................................................................................... 8
Work Area Safety ......................................................................................................................................... 8
Servicing Safety ........................................................................................................................................... 8
Troubleshooting .................................................................................................................. 9
Service and Maintenance.................................................................................................. 10
External Maintenance ................................................................................................................................ 10
Service and Maintenance Procedures ....................................................................................................... 10
Fluids ..........................................................................................................................................................11
Brake Maintnenance .................................................................................................................................. 12
Return to Neutral Setting Foot Control....................................................................................................... 13
Purging Procedures ................................................................................................................................... 14
Repair ................................................................................................................................. 15
General Instructions ................................................................................................................................... 15
Required Tools ........................................................................................................................................... 15
Torque Specifications ................................................................................................................................. 15
Transaxle Removal .................................................................................................................................... 15
Limited Disassembly .................................................................................................................................. 15
How To Use This Manual ........................................................................................................................... 16
Brake Assembly .................................................................................................................................... 17,18
Bypass Assembly ....................................................................................................................................... 19
Control Assembly .................................................................................................................................. 20,21
Seal Kit Replacement ................................................................................................................................ 22
Torque Bracket Assembly .......................................................................................................................... 23
Fan and Pulley Assembly ........................................................................................................................... 24
Input Shaft Assembly ................................................................................................................................. 25
Auxiliary Pump ........................................................................................................................................... 26
Charge Pump Assembly ............................................................................................................................ 27
Lower Housing/FIlter/Manifold Assembly .............................................................................................. 27,29
Planetary Differential Assembly ............................................................................................................ 30-33
Motor/Center Section/Pump Assembly ................................................................................................. 34-36
Directional Control Assembly ..................................................................................................................... 37
Transaxle Installation ................................................................................................................................. 38
Assembly After a Complete Teardown ....................................................................................................... 38
Sealant Application .................................................................................................................................... 39
Parts List ....................................................................................................................... 40-43
Glossary of Terms ........................................................................................................ 44,45
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FOREWORD
Headquartered in Sullivan, Illinois, Hydro-Gear®
is a world leader in the design, manufacture,
and service of quality hydrostatic transaxles for
the lawn and garden industry. The mission of
our company is to be recognized by our customers and the industry as a world-class supplier
and the quality leader in everything we do.
This Service and Repair Manual is designed
to provide information useful in servicing and
troubleshooting the Hydro-Gear -1500 or -1700
Integrated Hydrostatic Transaxle (IHT).
Also included is a glossary of terms that are
frequently used throughout the industry and
in Hydro-Gear service publications. Understanding terminology is very important!
It is necessary, and a good shop practice, that
your service area be equipped with the proper
tools and the mechanics be supplied the latest
information available. All repair procedures illustrated in this guide are suggested, but preferred methods of repair.
-1500/-1700 IHT
Repair procedures require that the transaxle
unit be removed from the vehicle.
This is not a certification, test or study guide for
a certification test. If a technician is interested
in certification, they should contact an agent
representing the OPEESA (Outdoor Power
Equipment and Engine Service Association)
at (860) 767-1770 or their Hydro-Gear Central
Service Distributor. Many distributors will be
hosting certification testing. These study guides
will cover most of the products and manufacturers in our industry.
For more information about Hydro-Gear or our
products, please contact your Central Service
Distributor, or call our Customer Service Department at (217) 728-2581.
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1
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
SECTION 1. DESCRIPTION AND OPERATION
INTRODUCTION
The purpose of this manual is to provide useful information for servicing the Hydro-Gear®
-1500/ -1700 Integrated Hydrostatic Transaxles
(IHT). This manual includes transaxle general description, hydraulic schematic, technical
specifications, product identification, safety,
troubleshooting, maintenance, and repair procedures.
The transaxle normally will not require servicing during the life of the vehicle in which it is
installed. Should other servicing be required,
the transaxle will need to be thoroughly cleaned
before beginning most procedures.
Please refer to the instructions titled “How to
Use This Manual” in the Repair Section for an
explanation of the layout of the disassembly,
inspection, and reassembly portions of this
manual.
GENERAL DESCRIPTION
The -1500/-1700 series transaxles are self contained units designed for the transfer and control of power. They provide an infinitely variable
speed range between zero and maximum in
both forward and reverse modes of operation.
The transaxle uses a variable displacement
pump with a maximum displacement of 10
cc per revolution, and motor with a fixed displacement of 21cc per revolution. The variable
displacement pump features a cradle swashplate with a direct-proportional displacement
control. Reversing the direction of the swash-
2
plate reverses the flow of oil from the pump
and thus reverses the direction of the motor
output rotation. The pump and motor are of the
axial piston design and utilize spherical nosed
pistons which are held against a thrust race by
internal compression springs.
The -1500/-1700 series transaxles have a self
contained fluid supply and an internal filter. The
fluid is drawn through the internal reservoir and
feeds the fixed displacement gerotor charge
pump. Excess fluid in the charge circuit is discharged over the charge relief valve and dumps
back to case. Charge check valves in the center
section are used to control the makeup flow of
the fluid to the low pressure side of the loop.
The transaxle is filled and tested at the factory
and should not require fluid or filter changes
unless the fluid becomes contaminated.
A cam style, block lifting bypass is utilized in the
-1500/-1700 series to permit moving the vehicle
for a short distance at a maximum speed of 2
m.p.h. (3.2 km/hr) without starting the engine.
WARNING
Actuating the bypass will result in the
loss of hydrostatic braking capacity. The
machine must be stationary on a level
surface and in neutral when actuating
the bypass.
The -1500/-1700 series transaxles utilize an
in-line floating disc brake controlled by a "cam"
style actuating arm.
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-1500/-1700 IHT
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HYDRAULIC SCHEMATIC
Figure 1. -1500 Hydraulic Schematic
Figure 2. -1700 Hydraulic Schematic
Figure 3. -1700 Hydraulic Schematic with Auxiliary Pump
-1500/-1700 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
HYDRAULIC SCHEMATIC
Figures 4 and 5 provide illustrations of the hydraulic oil circuit. The oil supply for the hydraulic
system of the IHT is also utilized for the lubrication of the planetary differential drive gears.
The input shaft and pump cylinder block are
turned in one direction only by the engine/drive
belt/pulley combination. Output of the oil flow
is controlled by the direction and amount that
the swashplate is angled. As the pump pistons
compress they force the oil to flow through one
of two passageways (forward or reverse) in
the center section (or valve body) to the motor
cylinder block and motor shaft. Since the motor has a fixed displacement angle it is forced
to turn with the flow of oil. As the angle of the
swashplate is increased the amount of oil being
pumped will increase and cause a higher RPM
output of the motor. Reversing the angle of the
pump swashplate will reverse the direction of
oil flow.
During the operation of the transaxle, fluid
is “lost” from the hydraulic loop through leak
paths designed into the product for lubrication
purposes (around pistons, under the rotating
cylinder blocks, etc.). This “lost” fluid returns
to the transmission housing and must be made
up in the loop. A charge pump is included on
the IHT to supply this makeup flow. The make
up flow is controlled (or directed) by the check
valves. Each check valve will either be held
opened or closed (depending upon the direction
of vehicle operation) by the system operating
pressure (closed) or by charge pressure (open)
from the charge pump.
The charge pump maintains a continuous flow
of oil as long as the input shaft is turning. All of
the oil being pulled into the charge pump first
must pass through an internal filter. Any oil not
needed by the transmission for make up flow
is discharged through the charge relief valve.
The charge relief valve maintains the charge
pressure.
The motor cylinder block mounts onto the
splined motor shaft which drives the planetary
differential gear/differential assembly.
The bypass feature in the IHT has a mechanical
lever which lifts the motor block off of the center
section running surface, allowing any oil flowing
from the pump block to be discharged into the
housing without turning the motor.
Figure 4. -1500 Hydraulic Flow Illustration
4
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-1500/-1700 IHT
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HYDRAULIC SCHEMATIC
Figure 5. -1700 Hydraulic Flow Illustration
-1500/-1700 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
EXTERNAL FEATURES
-1500 AND -1700
6
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-1500/-1700 IHT
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TECHNICAL
SPECIFICATIONS
Technical specifications for the -1500 and -1700
IHT’s are given in Table 1.
-1500
-1700
Overall Transaxle
Reduction
24.6:1
24.6:1
Input Speed (rpm)
3000 max.
1800 min.
3600 max.
1800 min.
20 in. (508 mm)
23 in. (584 mm)
Maximum Tire Diameter
Axle Shaft Diameter
1.00 in. (25.4 mm) 1.00 in. (25.4 mm)
4-Bolt Flange
4-Bolt Flange
Splined
Splined
Disc
Disc
53 lb. (24 kg)
53 lb. (24 kg)
Axle Shaft End Options
Brake Type
Weight of Unit
Table 1. Technical Specifications
PRODUCT IDENTIFICATION
The model and configuration of the -1500 or
-1700 IHT can be determined from the label
shown in Figure 6.
H Y D R O - G E A R
SULLIVAN, IL.
U.S.A.
Model
OEM
Model
Number
I IIII III IIII II II
165758
312-1700
310-3000
I II IIII IIII III III I II IIII
8 328 T1 476
Model
Hydro-Gear
Reference
Number
Number
Made in U.S.A.
Serial Number
Year Built
(unique number for that model - for that day)
Date
(Julian - day of year)
Type of Product and Build Information
Figure 6. -1700 Configuration Label
-1500/-1700 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
SECTION 2. SAFETY
This symbol points out important
safety instructions which, if not followed, could
endanger the personal safety and/or property
of yourself and others. Read and follow all
instructions in this manual before attempting
maintenance on your transaxle. When you see
this symbol - HEED ITS WARNING.
WARNING
POTENTIAL FOR SERIOUS INJURY
Inattention to proper safety, operation, or
maintenance procedures could result in
personal injury, or damage to the equipment. Before servicing or repairing the
IHT, fully read and understand the safety
precautions described in this section.
PERSONAL SAFETY
Certain safety precautions must be observed
while servicing or repairing the IHT. This section addresses some of these precautions but
must not be considered an all-inclusive source
on safety information. This section is to be
used in conjunction with all other safety material
which may apply, such as:
1) Other manuals pertaining to this machine
2) Local and shop safety rules and codes
3) Governmental safety laws and regulations
Be sure that you know and understand the
equipment and the hazards associated with it.
Do not place speed above safety.
Notify your supervisor whenever you feel there
is any hazard involving the equipment or the
performance of your job.
Never allow untrained or unauthorized personnel to service or repair the equipment.
8
Wear appropriate clothing. Loose or hanging
clothing or jewelry can be hazardous. Use the
appropriate safety equipment, such as eye
and hearing protection, and safety-toe and
slip-proof shoes.
Never use compressed air to clean debris from
yourself or your clothing.
TOOL SAFETY
Use the proper tools and equipment for the
task.
Inspect each tool before use and replace any
tool that may be damaged or defective.
WORK AREA SAFETY
Keep the work area neat and orderly. Be sure
it is well lit, that extra tools are put away, trash
and refuse are in the proper containers, and dirt
or debris have been removed from the working
areas of the machine.
The floor should be clean and dry, and all extension cords or similar trip hazards should be
removed.
SERVICING SAFETY
Certain procedures may require the vehicle to
be disabled in order to prevent possible injury
to the servicing technician and/or bystanders.
The loss of hydrostatic drive line power may
result in the loss of hydrostatic braking capability. Proper brake maintenance is very important
should this condition develop.
Some cleaning solvents are flammable. Use
only approved cleaning materials: do not use
explosive or flammable liquids to clean the
equipment.
To avoid possible fire do not use cleaning solvents in an area where a source of ignition may
be present
Discard used cleaning material in the appropriate containers.
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-1500/-1700 IHT
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SECTION 3. TROUBLESHOOTING
WARNING
Do not attempt any ser vic ing or adjust ments with the engine run ning.
Use extreme caution while inspecting
the drive belt assembly, and all vehicle
linkage!
Follow all safety procedures outlined in
the vehicle owner’s manual!
In many cases problems with the IHT are not related to a defective transmission or axle, but are
caused by slipping drive belts, partially engaged
bypass valves, and loose or damaged control
linkages. Be sure to perform all operational
checks and adjustments outlined in Section
4 before assuming the unit is malfunctioning.
Table 2 below provides a troubleshooting check
list to help determine the cause of operational
problems.
Table 2. Troubleshooting Checklist
Corrective Action
Possible Cause
Refer To:
UNIT OPERATES IN ONE DIRECTION ONLY
Control linkage bent or out of adjustment
Drive belt slipping or pulley damaged
Repair or replace linkage
Repair or replace drive belt or pulley
Control Linkage Repair, Page 23
Pulley Repair, Page 27
UNIT IS NOISY
Oil level low or contaminated oil
Excessive loading
Brake setting incorrect
Loose parts
Bypass assembly sticking
Air trapped in hydraulic system
Fill to proper level or change oil
Reduce vehicle loading
Adjust brake to proper setting
Repair or replace loose parts
Repair or replace valve or linkage
Purge hydraulic system
Fluid Maintenance, Page 11
Vehicle Specifications
Brake Adjustment, Page 12
Appropriate Repair Procedure
Bypass Repair, Page 22
Purging Procedure, Page 15
UNIT HAS NO/ LOW POWER
Engine RPM low
Control linkage bent or out of adjustment
Brake setting incorrect
Drive belt slipping or pulley damaged
Oil level low or contaminated oil
Excessive loading
Bypass assembly sticking
Air trapped in hydraulic system
Adjust to correct setting
Repair or replace linkage
Adjust brake to proper setting
Repair or replace drive belt or pulley
Fill to proper level or change oil
Reduce vehicle loading
Repair or replace valve or linkage
Purge hydraulic system
Vehicle Specifications
Control Linkage Repair, Page 23
Brake Adjustment, Page 12
Pulley Repair, Page 27
Fluid Maintenance, Page 11
Vehicle Specifications
Bypass Repair, Page 22
Purging Procedure, Page 15
UNIT OPERATING HOT
Debris buildup around transaxle
Brake setting incorrect
Cooling fan damaged
Oil level low or contaminated oil
Excessive loading
Air trapped in hydraulic system
Clean off debris
Adjust brake to proper setting
Repair or replace cooling fan
Fill to proper level or change oil
Reduce vehicle loading
Purge hydraulic system
Brake Adjustment, Page 12
Cooling Fan Repair, Page 27
Fluid Maintenance, Page 11
Vehicle Specifications Purging
Procedure, Page 15
TRANSAXLE LEAKS OIL
Damaged seals, housing, or gaskets
Air trapped in hydraulic system
-1500/-1700 IHT
Replace damaged component
Purge hydraulic system
Appropriate Repair Procedure
Purging Procedure, Page 15
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
SECTION 4. SERVICE AND MAINTENANCE
NOTE: Any servicing dealer attempting a warranty repair must have prior
approval be fore con duct ing main tenance of a Hydro-Gear® product unless the servicing dealer is a current
Authorized Hydro-Gear Service Center.
EXTERNAL MAINTENANCE
Reference Table 4., Page 16 for tools required
in the maintenance of the IHT.
Regular external maintenance of the IHT
should include the following:
1. Check the vehicle operator’s manual for
the recommended load ratings. Insure the
current application does not exceed load
rating.
2. Check oil level See Figure 7, Page 11.
3. Inspect the vehicle drive belt, idler pulley(s),
and idler spring(s). Insure that no belt slippage can occur. Slippage can cause low
input speed to the transaxle.
5. Inspect the axle parking brake and vehicle
linkage to insure proper actuation of the
parking brake.
6. Inspect the vehicle control linkage to the
directional control arm on transaxle. Also,
insure the control arm is securely fastened
to the trunnion arm of the transaxle.
7. Inspect the bypass mechanism on the transaxle and vehicle linkage to insure it actuates
and releases fully.
SERVICE AND
MAINTENANCE
PROCEDURES
All the service and maintenance procedures
presented on the following pages can be performed while the transaxle is mounted on the
vehicle. Any servicing beyond those given must
be performed after the unit has been removed
from the vehicle. Additional procedures are
provided in Section 5. Repair Procedures.
4. Inspect the transaxle cooling fan for broken or distorted blades and remove any
obstructions (grass clippings, leaves dirt,
etc.).
10
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-1500/-1700 IHT
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FLUIDS
FLUID CHANGE
The fluids used in Hydro-Gear® products have
been carefully selected, and only equivalent, or
better products should be substituted.
This transaxle is factory filled and does not
require a regular oil change. In the event of
oil contamination or degradation an oil change
may improve performance.
Typically, an engine oil with a minimum rating of
9 cSt (55 SUS) at 230° F (110° C) and an API
classification of SJ/CD is recommended. A
20W-50 engine oil has been selected for use
by the factory and is recommended for normal
operating temperatures.
FLUID VOLUME
Fluid volume information is provided in Table
3.
FLUID LEVEL
Certain situations may require additional fluid to
be added or even replaced. Refer to Figure 3
for the proper fill port and fluid level port locations. Fill the unit until fluid flows out of the fluid
level port. Recheck the fluid level once the unit
has been operated for approximately 1 minute.
Purging may be required. Refer to the purging
procedures, Page 14.
Fluid Description
20W-50 engine oil
Using the transaxle removal procedure from
Section 5, Page 15, remove the transaxle and
drain the oil from the top fluid fill port. Fill unit
per Table 3, reinstall the transaxle and perform
the purging procedures, Page 14.
In the event a fluid change and filter inspection
is required, refer to Page 27, Disassembly/Assembly instructions.
Caution
Do not overfill.
If you overfill the transaxle while the unit
is "cold", it may overflow as it reaches
normal operating temperatures. The oil
level should not be above the manufacturer’s suggestions outlined in this
manual. This will allow the space needed
for the oil to expand as it warms up.
Model
Volume
-1500
124.4 fl.oz. (3680 ml) to 129.5 fl.oz. (3830 ml)
-1700
106.2 fl.oz. (3140 ml) to 110.8 fl.oz. (3280 ml)
Table 3. Fluid Volumes for the -1500 and -1700 IHT
Figure 7. -1500 and -1700 Fluid Fill and Level Ports
-1500/-1700 IHT
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BRAKE MAINTENANCE
BRAKE SETTING
1. Remove the brake arm bias spring, and
then the cotter pin securing the brake castle
nut.
2. Insert a 0.015" (.381 mm) feeler gage between the brake disc and top brake puck,
and then set the brake by tightening or
loosening the castle nut.
3. Adjust brake gap to 0.015" (.381 mm) clearance.
4. Install the cotter pin to secure the castle nut,
and then install the brake arm bias spring.
12
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RETURN TO NEUTRAL SETTING
FOOT CONTROL
WARNING
POTENTIAL FOR SERIOUS INJURY
Certain procedures require the vehicle
engine to be operated and the vehicle to
be raised off of the ground. To prevent
possible injury to the servicing technician and/or bystanders, insure the
vehicle is properly secured.
The return to neutral mechanism on the transmission is designed to set the directional control into a neutral position when the operator
removes their foot from the foot control. Follow
the procedures below to properly adjust the
return to neutral mechanism on the transaxle:
1.
Confirm the transaxle is in the operating
mode (bypass disengaged). Raise the
vehicle’s drive tires off the ground to allow
free rotation.
NOTE: It may be necessary to remove
the drive tire from the axle hub to access
the linkage control and the transaxle
control arm.
3. Start the engine and increase the throttle to
full engine rpm.
4. Check for axle rotation. If the axles do not
rotate, go to Step 5. If the axles rotate, go
to Step 6.
5. Stop the vehicle’s engine. Adjust the OEM
linkage according to the OEM manual. Recheck according to Step 3 and 4. Stop the
vehicle engine. Refer to Figure 9.
6. Note the axle directional movement . Stop
the vehicle engine. Loosen the adjusting
puck screw until the puck can be rotated.
Rotate the adjusting puck the opposite direction of the wheel rotation on the control
linkage side in 5 degree increments. Tighten
the adjusting puck screw. Refer to Table 5.
Required Torque Values, Page 17. Recheck
according to Step 3 and 4. Stop the vehicle
engine. Adjust the OEM linkage according
to the OEM manual. Recheck according to
Step 3 and 4. Refer to Figure 9.
2. Remove the Original Equipment Manufacturer’s (OEM’s) control linkage at the control
arm. Refer to Figure 9.
WARNING
Do not attempt any adjustments with the
engine running. Use extreme caution
while inspecting all vehicle linkage!
Figure 9. Return to Neutral, Foot Control
Follow all safety procedures outlined in
the vehicle owner’s manual!
-1500/-1700 IHT
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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 normally 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", in the latter case, oil may
overflow.
Before starting, make sure the transaxle/ transmission is at the proper oil level. If it is not, fill
to the manufacturers suggestions outlined in
the vehicle owners manual.
The following procedures should be performed with the vehicle drive wheels off
the ground, then repeated under normal
operating conditions.
14
1. With the bypass valve open and the engine
running, slowly move the directional control
in both forward and reverse directions 6 to
10 times, as air is purged from the unit, the
oil level will drop and bubbles may appear in
the oil. After stopping the engine, add oil, as
necessary. Fill to the level outlined in Figure
7, Page 11.
2. With the bypass valve closed and the engine
running, slowly move the directional control
in both forward and reverse directions (6 to
10 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, purging is complete.
CAUTION
DO NOT OVERFILL.
If you overfill the transaxle while the unit
is "cold", it may overflow as it reaches
normal op er at ing tem per a tures. The
oil level should not be above the level
shown in figure 7, Page 11. This will allow
the space needed for the oil to expand
as it warms up.
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-1500/-1700 IHT
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SECTION 5. REPAIR
NOTE: Any servicing dealer attempting
a warranty repair must have prior approval before conducting maintenance
of a Hydro-Gear® product unless the
servicing dealer is a current Authorized
Hydro-Gear Service Center.
GENERAL INSTRUCTIONS
Cleanliness is a primary means of assuring
satisfactory life on repaired units. Thoroughly
clean all exposed surfaces prior to any type
of maintenance. Cleaning of all parts by using a solvent wash and air drying is usually
adequate. As with any precision equipment, all
parts must be kept free of foreign material and
chemicals.
Protect all exposed sealing surfaces and open
cavities from damage and foreign material. The
external surfaces should be cleaned before beginning any repairs.
Upon removal, it is recommended that all seals,
O-rings, and gaskets be replaced. During installation lightly lubricate all seals, O-rings, gaskets
with a clean petroleum jelly prior to assembly.
Also protect the inner diameter of seals by
covering the shaft with a cellophane (plastic
wrap, etc.).
Parts requiring replacement must be replaced
from the appropriate kits identified in the Items
Listing, found at the end of this manual.
REQUIRED TOOLS
A list of tools required for the repair of the -1500
or -1700 IHT is provided in Table 4, Page 17.
TORQUE SPECIFICATIONS
Torque specifications for fasteners used on the
-1500 and -1700 IHT are provided in Table 5.
-1500/-1700 IHT
TRANSAXLE REMOVAL
It is necessary to remove the -1500 or -1700
from the vehicle before performing the repair
procedures presented in this section. Use the
following procedure to prepare the unit for removal from the vehicle.
1. With the vehicle wheels on the ground,
loosen the nut (119, Figure 29) Page 40,
retaining the hub (118, Figure 29) on the
control side of the transaxle only. Use an
air impact wrench and a 1-1/8” socket to
loosen the hub.
2. Lift the vehicle wheels from the ground and
remove the nut completely.
3. Remove the wheel from the hub.
4. Using a wheel or gear puller, remove the
hub from the shaft.
CAUTION
USE CARE IN REMOVING THE HUB TO
PREVENT CRACKING.
LIMITED DISASSEMBLY
The following procedures are presented in
the order in which they must be performed
to completely disassemble the unit. Do not
disassemble the unit any farther than is necessary to accomplish the required repairs.
Each disassembly procedure is followed by a
corresponding assembly procedure, and the
disassembly process can be halted after any
given procedure.
Assembly is accomplished by performing the
assembly portions of the procedures. If the
unit has been completely disassembled, a
summary of the assembly procedures, in the
order in which they should occur, is given on
Page 38.
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HOW TO USE THIS
MANUAL
Many of the parts and subassemblies of this
transaxle can be removed and serviced independently of other components. The disassembly, inspection, and assembly portions of
this manual are therefore laid out in subsections. Each assembly is treated as a unit, and
the disassembly, inspection, and assembly
procedures follow one another.
Where some components and assemblies must
be removed before a given assembly can be
serviced, that information is given at the beginning of the disassembly instructions.
Subassemblies removed to reach another
component or feature need not be fully disassembled. They may be reassembled intact
following the necessary repairs.
Each assembly is provided with an exploded
view showing the parts involved. At the end of
the manual, after the reassembly summary, a
complete exploded views and items lists are
provided.
Sockets
3/8" Drive: 7/16", 1/2", 13/16"
1/2” Drive: 9/16", 15/16", 1-1/8"
#8 Internal Torx Drive
#10 Internal Torx Drive
Socket Drivers
3/8", 1/2"
Combination Wrenches
7/16", 1/2", 9/16", 13/16", 15/16", 1-1/8"
Miscellaneous
-1500/-1700 Service & Repair Manual
Loctite
Flat Blade Screw Driver
Torque Wrench
Air Impact Wrench
Pliers
Needle Nose
External Snap Ring
Internal Snap Ring
Allen Wrenches
5 mm, 6 mm, 1/4 inch
Table 4. Required Tools
Operation
Torque
Item
Center Section Screws (Item #44)
Lower Housing Screws (Item # 50)
Charge Pump Cover Screws (Item # 29)
Axle Shaft Jam Nut (Item # 73)
Right Hand Housing Screws (Item # 80)
Axle Hub Nut (Item # 119)
Pulley Nut (Item # 115)
Torque Bracket Nut (Item # 142)
Control Arm Stud (Item # 36)
Control Bearing Screw(Item # 92)
Control Arm Nut (Item # 95)
Adjusting Puck Screw (Item # 88)
Brake Nuts (Item # 127)
Differential Lock Sleeve Screws (Item #50)
525-700 lb-in (59-79 Nm)
135-185 lb-in (15-21 Nm)
87-108 lb-in (9-12 Nm)
660-800 lb-in (75-90 Nm)
230-290 lb-in (26-33 Nm)
200-295 lb-ft (271-400 Nm)
360-520 lb-in (41-59 Nm)
160-210 lb-in (18-24 Nm)
50-120 lb-in (6-14 Nm)
190-240 lb-in (22-27 Nm)
85-120 lb-in (10-14 Nm)
250-320 lb-in (28-36 Nm)
80-120 lb-in (9-14 Nm)
135-185 lb-in (15-21 Nm)
44
50
29
73
80
119
115
142
36
92
95
88
127
50
Description
Screw
Screw
M6 x 1-22
5/16-18
5/16-18
3/4-16
Jam Nut
5/16-18
5/16-24
Screw
5/16-24
5/16-24 x 1-3/4
1/4-20
Screw 1/4-20 x .75
Table 5. Required Torque Values
16
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-1500/-1700 IHT
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BRAKE ASSEMBLY
Refer to Figures 12 and 13.
4. Remove upper bolt (121) which secures
brake yoke assembly (122).
DISASSEMBLY
1. Remove the cotter pin (129), castle nut
(128), and washer (77).
2. Remove brake arm (124), and brake arm
bias spring (141).
3. Remove brake anti-drag compression spring
(151), and two brake pins (125).
REF.
2
77
85
120
121
122
124
125
128
Part Name
Right Hand Housing Assembly
Washer
Brake Disk
Brake Puck
Bolt
Brake Yoke Assembly
Brake Arm
Brake Pin
Castle Nut
5. Remove lower bolt (132), washer (139) and
spacer (130) which secure the brake yoke
assembly (122).
6. Remove brake yoke assembly (122), puck
plate (131), and outer brake puck (120).
7. Remove brake disc (85), and inner brake
puck (120).
REF. Part Name
129 Cotter Pin
130 Spacer
131 Puck Plate
132 Bolt
139 Washer
141 Brake Arm Bias Spring
151 Anti-Drag Compression
Spring
Figure 12. Brake Assembly
-1500/-1700 IHT
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17
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
INSPECTION
1. Inspect the brake pucks (120) for excessive
wear.
6. Install brake anti-drag compression spring
(151), and two brake pins (125).
2. Replace with new if necessary.
7. Install brake arm (124) onto brake yoke assembly.
ASSEMBLY
1. Install inner brake puck (120), and brake
disc (85).
2. Assemble the brake yoke assembly, by installing puck plate (131), outer brake puck
(120) into brake yoke (122).
3. Position the brake yoke assembly against
the brake disc.
8. Install washer (77), and castle nut (128).
9. Insert a (0.015”) (.381 mm) feeler gage between brake disc (85) and outer brake puck
(120). Adjust the brake by turning castle nut
(128) until it is snug but not tight against the
feeler gage. (The brake gap must be adjusted to a (0.015”) (.381 mm) clearance.
4. Install the upper bolt (121).
10. Install cotter pin (129) to secure castle nut
(128).
5. Install the lower bolt spacer (130), washer
(139) and bolt (132) to secure the brake
yoke assembly (122).
11. Install brake arm bias spring (141) to brake
arm (124) and lower brake yoke assembly
bolt (132).
18
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-1500/-1700 IHT
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BYPASS ASSEMBLY
Refer to Figure 14.
DISASSEMBLY
1. Remove retaining ring (42).
2. Remove bypass arm (41).
3. Remove bypass lip seal (40).
INSPECTION
1. Inspect bypass arm (41) for wear.
ASSEMBLY
1. Install bypass lip seal (40). See Page 25 for
instructions.
2. Install bypass arm (41).
3. Install retaining ring (42).
-1500/-1700 IHT
REF.
40
41
42
Part Name
Lip Seal
Bypass Arm
Retaining Ring
Figure 14. Bypass Assembly
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19
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
CONTROL ARM ASSEMBLY
Refer to Figure 15, Page 21
DISASSEMBLY
CONTROL ARM ASSEMBLY
RETURN TO NEUTRAL ASSEMBLY
1. Remove screw (88) and adjusting puck
(48).
2. Remove neutral spring (46), return arm (34),
and washer (87).
CONTROL ARM ASSEMBLY
1. Remove lower lock nut (95), and trunnion
spacer (106), from the trunnion arm (31).
2. Remove control arm (26).
3. Remove stud (36), if necessary.
INSPECTION
1. Inspect bearing (89), and replace if neces sary. Remove bear ing by removing
countersink screw (92), and spacer (90).
2. Inspect trunnion arm lip seal (33) and
replace if necessary. See page 22 for replacement instructions.
20
ASSEMBLY
1. Install new trunnion arm lip seal (33), into
main housing (1). See page 22 for instructions.
2. Install stud (36), per Table 5, Page 16.
3. Install control arm (26), onto trunnion arm
(31) and stud (36).
4. Install trunnion spacer (106) and lock nut
(95), per table 5, Page 16, onto the trunnion
arm (31).
NEUTRAL ASSEMBLY
NOTE: If bearing (89) must be replaced,
install bearing (89), spacer (90), and
countersink screw (92).
1. Install washer (87), return arm (34) and
neutral spring (46).
2. Install adjusting puck (48), and bolt (88).
3. Reference page 13 for proper neutral adjustment procedures.
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-1500/-1700 IHT
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REF.
26
31
32
33
34
36
46
48
Part Name
Control Arm
Trunnion Arm
Trunnion Bushing
Lip Seal
Return Arm
Stud
Spring
Adjusting Puck
REF.
87
88
89
90
92
95
106
Part Name
Washer
Screw
Bearing
Locating Spacer
Countersink Screw
Locknut
Trunnion Spacer
Figure 15. Control Arm Assembly
-1500/-1700 IHT
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21
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
SEAL KIT REPLACEMENT
Before disassembly, wipe the unit free of any
debris to avoid contamination.
Refer to Figure 16.
REF.
1
5
7
33
40
41
42
75
84
116
Part Name
Main Housing
Lip Seal
Retaining Ring
Lip Seal
Lip Seal
Bypass Arm
Retaining Ring
Seal
Lip Seal
Retaining Ring
Figure 16. Seal Replacement Kit
INPUT SEAL
1. Remove the input pulley from the input
shaft.
2. Remove the seal retaining ring (7).
3. Carefully pull the input seal (5) out of the
housing bore with a “hook” type tool. Care
must be taken to avoid damage to the housing bore or shaft sealing area.
4. Lubricate the new seal with petroleum jelly
prior to installation.
5. Wrap the shaft keyway (splines) with cellophane to prevent damage to the seal lip
during installation.
6. Slide the seal over the shaft and press it into
the housing bore.
7. The seal should seat against the spacer.
8. Install the seal retaining ring (7) and make
sure it is fully seated in its groove.
AXLE SEAL
1. The seal (75) can be replace by following
steps 2-6 of the procedure used to replace
the input seal.
22
2. Install the retaining ring (116) and make sure
it is fully seated in its groove.
MOTOR SHAFT SEAL
1. Remove the brake assembly. See Pages
17-18.
2. The seal (84) can be replaced by following
steps 3-6 of the procedure used to replace
the input shaft.
TRUNNION SEAL
1 Remove the control arm and any attachments to the control arm. See Page 20.
2. The seal (33) can be replaced by following
steps 3-6 of the procedure used to replace
the input shaft.
BYPASS SEAL
1. Remove the bypass arm and any attachments to the bypass arm. See Page 19.
2. Remove the bypass rod seal (40). Deburr
the bypass rod.
3. Install the seal (40). Install the bypass arm
(41) and retaining ring (42).
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-1500/-1700 IHT
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TORQUE BRACKET
ASSEMBLY (IF EQUIPPED)
Refer to Figure 17.
DISASSEMBLY
1. Remove lock nut (142), and bolt (143), from
torque bracket (102).
2. Remove torque bracket (102), from main
housing (1).
ASSEMBLY
1. Install torque bracket (102), onto main housing (1).
2. Install lock nut (142), and bolt (143), to secure torque bracket (102) to main housing
(1). Reference Table 5, Page 16 for torque
values.
-1500/-1700 IHT
REF.
1
102
142
143
Part Name
Main Housing
Torque Bracket
Lock Nut
Bolt
Figure 17. Torque Bracket Assembly
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23
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
FAN AND PULLEY
ASSEMBLY
Refer to Figure 18.
DISASSEMBLY
1. Remove jam nut (115) and slotted washer
(107) from input shaft (12).
2. Remove fan/pulley assembly (104) and
(103).
INSPECTION
1. Inspect fan (104) for broken and/or damaged
blades. If necessary to replace fan (104),
remove fan (104), from pulley (103).
ASSEMBLY
1. Install fan/pulley assembly (104) and (103)
onto input shaft (12).
2. Secure fan/pulley assembly (104) and (103)
onto shaft (12) by installing slotted washer
(107) and jam nut (115), per table 5, Page
16.
24
REF.
1
12
103
104
107
115
Part Name
Main Housing
Input Shaft
Pulley
Fan
Slotted Washer
Jam Nut
Figure 18. Fan and Pulley Assembly
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-1500/-1700 IHT
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INPUT SHAFT ASSEMBLY
Refer to Figure 19.
DISASSEMBLY
1. Drain the oil from the transaxle by opening
the fill port or level port and positioning the
unit so the oil drains. If equipped, open the
oil drain port. See page 6 for location.
2. If replacing the input shaft only, continue
with step 3. If further disassembly of the
unit is required, leave the input shaft in
the transaxle at this time and proceed to
the next page.
REF.
1
4
5
6
7
8
12
13
Part Name
Main Housing
Spacer
Lip Seal
Wire Retaining Ring
Snap Ring
Ball Bearing
Input Shaft
Block Thrust Washer
3. Remove the snap ring (7), input shaft lip
seal (5), and spacer (4).
4. Remove the input shaft assembly which
consists of the input shaft (12), ball bearing (8) and retaining ring (6).
5. Remove washer (13) from the input shaft
bore.
Figure 19. Input Shaft Assembly
INSPECTION
1. Inspect bearing (8) for damage and, if
necessary replace bearing, remove wire
retaining ring (6) and bearing (8) from input
shaft (12).
ASSEMBLY
1. Carefully install washer (13) onto top of
spring in the input shaft bore.
2. Press bearing (8) onto input shaft (12) and
secure by installing wire retaining ring (6).
3. Install input shaft assembly (items 12, 8 and
6) into input bearing bore of main housing
(1).
4. Install spacer (4) into the input bearing
bore.
5. Install the input shaft lip seal (5). See page
25.
6 Secure input shaft assembly (12) by installing retaining ring (7).
7. Fill the unit with new motor oil. See page
11.
-1500/-1700 IHT
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25
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
AUXILIARY PUMP
ASSEMBLY (IF EQUIPPED)
Refer to Figure 20.
DISASSEMBLY
1. Remove two screws (29) from the auxiliary
pump cover (54), and remove the cover
(54).
2. Remove o-ring (53), gerotor assembly (52),
shim (162) and pins (163).
INSPECTION
1. Inspect gerotor assembly (52), pump cover
(54), for damage or excessive wear.
ASSEMBLY
1. Install gerotor (52) with new o-ring (53) onto
input shaft (12) (not shown).
2. Install new O-ring (53) into pump cover
(54).
REF.
1
29
52
53
54
162
163
Part Name
Main Housing
Screw
Gerotor Assembly
O-ring
Pump Cover
Shim
Pin
Figure 20. Auxiliary Pump Assembly
3. Install pins (163) and shim (162) onto the
pump cover (54).
4. Install cover (54) and secure by installing
two screws (29), per Table 5, Page 16.
26
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-1500/-1700 IHT
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CHARGE PUMP ASSEMBLY
(IF EQUIPPED)
LOWER HOUSING/FILTER
ASSEMBLY (-1500)
Refer to Figure 21.
Refer to Figure 22.
DISASSEMBLY
DISASSEMBLY
NOTE: Before disassembling, note the
orientation of the charge pump cover
(54). Scribe or mark the charge pump
cover (54) for correct orientation during
assembly.
1. Remove two screws (29) from the charge
pump cover (54), and remove the charge
pump cover (54).
2. Remove the o-ring (53) and gerotor assembly (52) from the charge pump cover
(54).
INSPECTION
1. Inspect gerotor assembly (52) and the
charge pump cover (54) for damage or
excessive wear.
ASSEMBLY
1. Install gerotor (52) onto input shaft (12) (not
shown).
2. Install new O-ring (53) into charge pump
cover (54).
1. Remove the eleven housing screws (50) and
lower cover (51), and remove sealant from
the housing and lower cover (51).
2. Remove filter (55) from the center section
assembly (3) (not shown).
INSPECTION
1. Inspect filter (55), replace if necessary.
NOTE: Filter replacement is suggested.
ASSEMBLY
1. Install filter (55) onto the center section (3)
(not shown).
2. Apply sealant (79) to lip of main housing (1).
See Figure 30, Page 39 for sealant path.
3. Secure lower cover (51) to main housing
(1) by installing the eleven housing screws
(50), reference Table 5, Page 16.
3. Install charge pump cover (54), making sure
it is properly oriented.
4. Secure charge pump cover (54) by installing
two screws (29), per Table 5, Page 16.
REF.
1
29
52
53
54
REF.
1
50
51
55
Part Name
Main Housing
Screw
Gerotor Assembly
O-Ring
Gerotor Cover
Figure 21. Charge Pump Assembly
-1500/-1700 IHT
Part Name
Main Housing
Screw
Lower Cover
Filter
Figure 22. Lower Housing/Filter Assembly/ -1500
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27
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
LOWER HOUSING/FILTER/
MANIFOLD ASSEMBLY
-1700 (STANDARD CHARGE PUMP)
8. Secure lower cover (51) to main housing
(1) by installing the eleven housing screws
(50), reference Table 5, Page 17.
Refer to Figure 23.
NOTE: Charge Pump assembly must be
removed before the following steps can
be performed. See page 30.
DISASSEMBLY
1. Remove the eleven housing screws (50) and
lower cover (51), and remove sealant.
2. Remove screw O-rings (157).
3. Remove spring (145) and ball (146).
4. Remove filter (55) and charge manifold
(56).
5. Remove o-ring (144).
INSPECTION
1. Inspect filter (55) and manifold (56), replace
if necessary.
NOTE: Filter replacement is suggested.
2. Inspect o-ring (144) and screw O-rings
(157).
ASSEMBLY
1. Install o-ring (144) onto center section assembly (3), refer to Figure 27.
2. Install filter (55) and charge manifold (56).
3. Install spring (145) and ball (146).
4. Install screw O-rings (157).
5. Dry fit lower cover (51) on housing, using
screws (29) to align cover and manifold
(56).
6. Remove screws (29) and cover (51). Apply
sealant (79) to lip of main housing (1). See
Figure 30, Page 39 for sealant path.
REF.
1
29
50
51
52
53
54
Part Name
Main Housing
Capscrew
Screws
Lower Cover
Gerotor Assembly
O-Ring
Gerotor Cover
REF.
55
56
144
145
146
157
Part Name
Filter
Charge Manifold
O-Ring
Spring
Ball
Screw O-Ring
Figure 23. Lower Housing/Filter/Manifold Assembly
7. Reinstall cover (51) and screws (29), reference Table 5, Page 16.
28
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LOWER HOUSING/FILTER/
MANIFOLD ASSEMBLY/
-1700 (AUXILIARY CHARGE
PUMP)
Refer to Figure 23A.
NOTE: Charge Pump assembly must be
removed before the following steps can
be performed. See page 26.
DISASSEMBLY
1. Remove the eleven housing screws (50) and
lower cover (51), and remove sealant.
2. Remove filter (55) and charge manifold
(56).
3. Remove o-ring (144).
INSPECTION
1. Inspect filter (55) and manifold (56), replace
if necessary.
NOTE: Filter replacement is suggested.
2. Inspect o-ring (144).
ASSEMBLY
1. Install o-ring (144) onto center section assembly (3), refer to Figure 27.
2. Apply sealant to filter (55) before assembling
with charge manifold (56).
REF.
1
29
49
50
Part Name
Main Housing
Capscrew
Aux. Pump Assy.
Screws
REF.
51
55
56
144
Part Name
Lower Cover
Filter
Charge Manifold
O-Ring
Figure 23A. Lower Housing/Filter/Manifold Assembly
3. Install filter (55) and charge manifold (56).
4. Dry fit lower cover (51) on housing, using
screws (29) to align cover and manifold
(56).
5. Remove screws (29) and cover (51). Apply
sealant (79) to lip of main housing (1). See
Figure 30, Page 39 for sealant path.
6. Reinstall cover (51) and screws (29).
7. Secure lower cover (51) to main housing
(1) by tightening the eleven housing screws
(50), reference Table 5, Page 16.
-1500/-1700 IHT
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29
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
PLANETARY DIFFERENTIAL
ASSEMBLY W/O DIFF. LOCK
Refer to Figure 24, next page.
NOTE: Brake Assembly, and optional
Return to Neutral have to be removed
before the following steps can be performed.
DISASSEMBLY
1. Remove the axle hub assembly (118) on
control side by removing nuts (119), and
hub assemblies (118).
2. Remove the eight torx head screws (80) and
one shouldered torx head screw (168) that
secure the R.H. housing assembly (2).
3. Remove R.H. housing axle seal. See page
22.
4. Remove R.H. housing assembly (2), while
holding axle shaft (76) in place.
5. Remove the two housing pins (117).
6. Remove washer (71) from axle shaft (76).
7. Remove spur gear (60), and thrust plate
(62).
8. Remove 21T sun gear (61), and sleeve
bearing (96).
9. Remove the planetary gears (59).
16. See page 22 for axle shaft seal removal.
INSPECTION
1. Inspect all gears for excessive wear or damage and replace if necessary.
2. Remove all sealant from both housings and
inspect seal lands for damage when cleaning.
3. If bevel gear (65) needs replacing, remove
jam nut (73) from axle shaft (76).
ASSEMBLY
1. If necessary, install L.H. Axle shaft assembly (76) into main housing (1). If necessary,
reassemble axle shaft assembly (76) by installing washer (71), bevel gear (65), and
jam nut (73) onto axle shaft (76).
2. Install differential thrust plate (68) into main
housing (1).
3. Install planetary carrier (64) into main housing (1).
4. Reassemble the two bevel gears (66) onto
differential shaft (67), and install assembly
into planetary carrier (64).
5. Install 51T ring gear (63) into main housing
(1).
6. Install the four carrier pins (58) into planetary
carrier (64).
11. Remove the four carrier pins (58) from planetary carrier (64).
7. If necessary, reassemble axle shaft assembly (76) by installing washer (71), bevel
gear (65), and jam nut (73) onto axle shaft
(76).
12. Remove 51T ring gear (63) from main housing (1).
8. Install R.H. Axle shaft assembly (76) partway
into assembled differential components.
13. Remove the two bevel gears (66), and differential shaft (67).
NOTE: It will be necessary to support the
RH axle shaft in the partially installed
position while steps 9 through 16 are
completed.
10. Remove the axle shaft (76).
14. Remove planetary carrier (64) and differential thrust plate (68).
15. If necessary, remove the axle seal and second axle shaft assembly (76) from main
housing (1).
30
9. Assemble sleeve bearing (96) and sun gear
(61), sliding them onto R.H. axle shaft. The
smaller diameter on the sun gear OD should
be “IN”.
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-1500/-1700 IHT
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REF.
1
2
58
59
60
61
62
63
64
65
66
67
68
Part Name
Main Housing
R.H. Housing Assembly
Carrier Pin
Planetary Gears
64T Spur Gear
21T Sun Gear
Planetary Thrust Plate
REF. Part Name
51T Ring Gear
69 Flange Bearing
Planetary Carrier
71 Washer
Bevel Gear (Splined)
73 Hex Jam Nut
Bevel Gear (Cross Shaft)
76 Axle Shaft
Differential Shaft
80 Torx Head Screws
Differential Thrust Plate
96 Bearing Sleeve
REF.
117
118
119
168
Part Name
Housing Pin
Axle Hub Assembly
Hex Nut
Torx Head Screw
Figure 24. Planetary Gear Reduction and Differential Assembly
10. Install the four 15T planetary gears (59) on
pins (80) . Make sure the planetary gears
are properly aligned with the sun gear (61).
Mate the bevel gear (65) on the end of the
RH axle shaft with the bevel gears (66) in
the differential assembly. Continue to support the RH axle shaft.
15. Apply a bead of sealant to the main housing.
16. Install R.H. housing (2) by sliding it down the
axle shaft (76), over motor shaft assembly
(24, Figure 27) and onto main housing (1).
11. Install the planetary thrust plate (62).
17. Secure housings by installing the eight
housing screws (80) and one shouldered
torx screw (168), per Table 5, Page 16.
12. Install the 64T spur gear (60) onto the 21T
sun gear (61).
18. Install the axle shaft seals. See page 22.
13. Slide washer (71) onto axle shaft (76).
14. Install the two housing pins (117) into the
main housing (1).
-1500/-1700 IHT
19. After the transaxle has been installed in
the vehicle, install the axle hub assemblies (118), according to the instructions in
“Transaxle installation”, Page 37.
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31
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
PLANETARY DIFFERENTIAL
ASSEMBLY W/ DIFF. LOCK
Refer to Figure 25, next page.
NOTE: Brake Assembly, and optional
Return to Neutral have to be removed
before the following steps can be performed.
18. Remove differential components washer
guide (177), relief springs (145), dogs (175),
load plate (173), washer (172), rotating cam
(171) and stationary cam (170).
INSPECTION
1. Inspect all gears for excessive wear or damage and replace if necessary.
DISASSEMBLY
2. Remove all sealant from both housings and
inspect seal lands for damage when cleaning.
1. Remove retaining ring (182), and actuating
handle (181).
3. If bevel gear (65) needs replacing, remove
jam nut (73) from axle shaft (76).
2. Remove screws (50), sleeve (180), o-ring
(184), cam (178) and shaft (179) from the
main housing.
ASSEMBLY
3. Remove the axle hub assembly (118) on
control side by removing nuts (119), and
hub assembly (118).
4. Remove the axle seal. See page 25.
5. Remove the eight torx head screws (80) and
one shouldered torx head screw (168) that
secure the R.H. housing assembly (2).
6. Remove R.H. housing assembly (2), while
holding axle shaft (76) in place.
7. Remove the two housing pins (117).
8. Remove washer (71) from axle shaft (76).
9. Remove spur gear (60), and thrust plate
(62).
10. Remove 21T sun gear (61), and sleeve
bearing (96).
11. Remove the planetary gears (59).
12. Remove the axle shaft (76).
13. Remove the four carrier pins (58) from planetary carrier (64).
14. Remove 51T ring gear (63) from main housing (1).
15. Remove the two bevel gears (66), and differential shaft (67).
16. Remove planetary carrier (64) and differential thrust plate (68).
17. If necessary, remove the second axle shaft
assembly (76) from main housing (1). See
page 22 for axle seal removal.
32
1. If necessary, install L.H. Axle shaft assembly
(76) into main housing (1). If necessary,
reassemble axle shaft assembly (76) by
installing washer (71), bevel gear (65), and
jam nut (73) onto axle shaft (76).
2. Install stationary cam (170), rotating cam
(171), washer (172), load plate (173), dogs
(175), washer guide (177) and relief springs
(145) into the main housing (1).
3. Install differential thrust plate (68) into main
housing (1).
4. Install planetary carrier (64) into main housing (1).
5. Reassemble the two bevel gears (66) onto
differential shaft (67), and install assembly
into planetary carrier (64).
6. Install 51T ring gear (63) into main housing
(1).
7. Install the four carrier pins (58) into planetary
carrier (64).
8. If necessary, reassemble axle shaft assembly (76) by installing washer (70), bevel
gear (65), and jam nut (73) onto axle shaft
(76).
9. Install R.H. Axle shaft assembly (76) partway
into assembled differential components.
NOTE: It will be necessary to support the
RH axle shaft in the partially installed
position while steps 10 through 17 are
completed.
10. Assemble sleeve bearing (96) and sun gear
(61), sliding them onto R.H. axle shaft. The
smaller diameter on the sun gear OD should
be “IN”.
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REF.
1
2
58
59
60
61
62
63
64
65
66
67
68
69
70
71
73
76
80
Part Name
Main Housing
R.H. Housing Assembly
Carrier Pin
Planetary Gears
64T Spur Gear
REF. Part Name
21T Sun Gear
96 Bearing Sleeve
Planetary Thrust Plate
117 Housing Pin
51T Ring Gear
118 Axle Hub Assembly
Planetary Carrier
119 Hex Nut
Bevel Gear (Splined)
145 Relief Spring
Bevel Gear (Cross Shaft) 168 Screw, Shouldered Torx Head
Differential Shaft
170 Cam, Stationary
REF. Part Name
Differential Thrust Plate
171 Cam, Rotating
180 Sleeve
Flange Bearing
172 Washer
181 Handle, Actuating
Washer
173 Load Plate
182 Ring, Retaining
Washer
175 Dog, Engagement
183 O-Ring
Hex Jam Nut
177 Washer Guide
184 O-Ring
Axle Shaft
178 Cam, Actuating
203 Seal Kit
Torx Head Screws
179 Shaft
210 Nut, Lug
Figure 25. Planetary Gear Reduction and Differential Assembly
11. Install the four 15T planetary gears (59) on
pins (80) . Make sure the planetary gears
(59) are properly aligned with the sun gear
(61). Mate the bevel gear on the end of the
RH axle shaft with the bevel gears (66) in
the differential assembly. Continue to support the RH axle shaft.
12. Install the planetary thrust plate (62).
13. Install the 64T spur gear (60) onto the 21T
sun gear (61).
14. Slide washer (71) onto axle shaft (76).
15. Install the two housing pins (117) into the
main housing (1).
18. Secure housings by installing the eight
housing screws (80) and one shouldered
torx screw (168), per Table 5, Page 17.
19. Assemble shaft (179), cam (178), o-ring
(183) and o-ring (184) into sleeve (180) then
install sleeve assembly into main housing
(1).
NOTE: Make sure tab from cam (178) fits
into slot in rotating cam (171).
20. Secure sleeve assembly (180) with screws
(50).
21. Install actuating lever (181) and retaining
ring (182).
16. Apply a bead of sealant to the main housing
(1). See page 39 for sealant path
22. Install new axle seals. See page 22.
17. Install R.H. housing (2) by sliding it down the
axle shaft (76), over motor shaft assembly
(24, Figure 27) and onto main housing (1).
23. After the transaxle has been installed in
the vehicle, install the axle hub assemblies (118), according to the instructions in
“Transaxle installation”, Page 37.
-1500/-1700 IHT
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33
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
MOTOR/CENTER SECTION/
PUMP ASSEMBLY
Refer to Figures 26 and 27, (next pages).
NOTE: Brake Assembly, Charge Pump
Assembly, Differential Assembly, and
Lower Housing/Filter/Manifold Assembly
have to be removed before the following
steps can be performed.
DISASSEMBLY
1. Remove the motor shaft assembly which
consists of the washer (82), snap ring (83),
washer (82), 16T pinion gear (28), spacer
(27), and shaft (24).
2. Remove motor thrust bearing re tain er
(57).
3. Remove the three screws (44) from center
section assembly (3).
4. Lift center section assembly (3) and motor
block assembly (21) out of main housing
(1).
5. Remove each piston (23), spring (18), and
piston seat (22) from the 21cc motor cylinder
block assembly.
6. Remove motor thrust bearing (25).
7. Remove bypass plate (38) from center section assembly (3).
8. Remove the two center section assembly
pins (43).
9. Remove bypass actuator (39) from the center section (3).
INSPECTION
1. Inspect running surface of thrust bearing
(25) for excessive wear.
2. Inspect each piston (23), spring (18), and
piston seat (22) in the motor cylinder block
assembly.
3. Inspect seal lands of the 21cc motor cylinder block assembly (21) for excessive
wear (grooving or smearing).
4. Inspect the two running surfaces of center
section assembly (3) for excessive wear
(grooving or smearing). Abnormal wear
patterns will usually be visible. Any wear
detectable when a fingernail is dragged
across the surface is cause for rejection.
5. Inspect each piston (17), spring (18), piston seat (16) in the pump cylinder block
assembly.
6. Inspect seal lands of 10cc pump cylinder
block assembly (15) for excessive wear
(grooving or smearing).
ASSEMBLY
1. Install input shaft assembly (12, Figure
19).
2. Install pump cylinder block thrust washer
(13) and spring (14) onto input shaft assembly (12, Figure 19).
3. Install piston washers (18), springs (17), and
pistons (18) in to the pump cylinder block
(15).
11. Remove each piston (17), spring (18), piston
seat (16) from the 10cc pump cylinder block
assembly (21).
4. Install pump cylinder block assembly (15)
onto the input shaft (12). Be sure spring
tension is even around the entire block. To
assist in cylinder block installation, a rubber
band can be placed around all of the pistons
to hold them in position. After the cylinder
block is installed, cut the rubber band and
remove it from the the housing.
12. Remove block spring (14), and block thrust
washer (13) from shaft (12, Figure 19).
5. Install the two center section assembly pins
(43).
13. Remove the input shaft if not already removed. See page 25.
6. Install the bypass actuator (39) into the
center section (3).
10. Remove 10cc pump cylinder block assembly
(15).
34
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7. Install center section assembly (3) into main
housing (1). Make sure center section seats
fully on its mating surface.
8. Secure center section assembly (3) by installing three screws (44) reference Table
5, Page 13. Apply a few drops of loctite on
screws when installing.
9. Install bypass plate (38) into center section
assembly (3).
NOTE: To hold bypass plate (38) in position, apply a small drop of grease to its
slot before installing.
10. Install spacer (27), 19T pinion gear (28),
washer (82), snap ring (83), and washer
(82) onto motor shaft (24).
11. Install piston washers (18), springs (17), and
pistons (16) into the motor cylinder block
(21).
12. If not already available, make an assembly
tool from 28 ga. sheet metal as shown in
Figure 26. The assembly tool must be free
of burrs and rough edges.
13. Using the assembly tool to compress pistons
(22), install motor cylinder block assembly
(21). Be careful not to dislodge bypass plate
(38) when installing the motor cylinder block
assembly.
14. Again using the assembly tool to compress
pistons (22), slide thrust bearing (25), behind the tool, into its cavity in front of the
motor cylinder block assembly (21).
NOTE: The thick race of thrust bearing
(25) must face the pistons.
15. While holding the cylinder block assembly
(21) and the thrust bearing (25) in place,
withdraw the assembly tool from between
the thrust bearing and the pistons.
16. Install motor thrust bearing retainer (57).
17. Insert the motor shaft assembly (24) far
enough into the center section (3) to seat
and engage the motor cylinder block (21).
18. Reassemble the planetary differential assembly and install removed components
as directed in their respective assembly
procedures.
Break sharp edges, both sides
Use 28 gauge
sheet metal
2.250 inch
1.125 Radius
6.000 inch
Figure 26. Motor Cylinder Block Assembly Tool
-1500/-1700 IHT
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35
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
REF.
1
3
13
14
15
16
17
18
19
Part Name
Main Housing
Center Section Assembly
Block Washer
Block Spring
10cc Cylinder Block
Pistons
Springs
Piston Washers
Block Spring
REF.
20
21
22
23
24
25
27
28
38
Part Name
Bushing
21cc Cylinder Block
Pistons
Springs
Motor Shaft
Thrust Bearing
Spacer
19T Pinnion Gear
Bypass Plate
REF. Part Name
39
43
44
53
57
82
83
144
Bypass Actuator
Pin
Screws
O-Ring
Bearing Retainer
Washer
Retaining Ring
O-ring
Figure 27. Motor/Center Section/Pump Assembly
36
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DIRECTIONAL CONTROL
ASSEMBLY
Refer to Figure 28.
NOTE: The Motor/Center Section/Pump
Assembly must be disassembled before
this procedure can be completed.
DISASSEMBLY
1. Remove swashplate assembly (10). Disassemble swashplate assembly by removing
thrust bearing (11) from swashplate (10). The
thick race of thrust bearing must face pistons.
2. Remove slot guide (30) from the trunnion
arm (31).
3. Remove the trunnion arm (31) from the main
housing (1).
REF.
1
9
10
11
30
31
Part Name
Main Housing
Cradle Bearing
Variable Swashplate
Thrust Bearing
Slot Guide
Trunnion Arm
Figure 28. Directional Control Assembly
INSPECTION
1. Visually inspect (in place) the two cradle
bearings (9), which are staked in main housing. Do not remove the Cradle Bearings (9)
from housing (1).
ASSEMBLY
1. Install the trunnion arm in the main housing
(1).
2. Install slot guide (30) onto the trunnion arm
(31).
3. Assemble swashplate assembly (10) by installing thrust bearing (11) into swashplate
(10).
Note: Assemble thrust bearing with thick
race facing pistons.
4. Install swashplate assembly (10) into main
housing (1). The swashplate (10) will couple
with slot guide (30).
NOTE: When installing swashplate assembly (10), use flat head screwdriver
to hold slot guide (30) in place.
5. Rotate the trunnion arm to confirm proper
swashplate movement.
-1500/-1700 IHT
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37
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
TRANSAXLE INSTALLATION ASSEMBLY AFTER A
Use the following procedure to complete instal- COMPLETE TEAR-DOWN
lation of the transaxle on the vehicle.
1. Install and secure the transaxle on the vehicle according to instructions in the vehicle
owner’s manual.
2. Install the hub assembly (118, Figure 29) on
the shaft. Install hex nut (119, Figure 29).
If the unit has been torn down completely, the
following summary identifies the assembly
procedures necessary to completely assemble
the unit, in the order they must be completed.
Each assembly procedure is located by a page
reference.
3. With the vehicle raised, install the wheel
on the hub, and retain with the wheel lug
nuts.
The part reference numbers provided in each
assembly procedure are keyed to the individual
exploded views, and are also keyed to the complete unit exploded view, Figure 29.
4. Lower the vehicle wheels to the ground, and
torque the nut retaining the hub to 290 to
295 lb.-ft., using an air impact wrench.
1. Assemble the Directional Control Assembly
(Page 37).
5. Tighten the wheel lug nuts. Consult the
vehicle owner’s manual for proper torque.
2. Assemble the Motor/Center Section/Pump
Assembly (Page 34,35,36).
3. Assemble the Planetary Gear Reduction and
Differential Assembly (Page 30,31,32,33).
4. Assemble the Lower Housing/Filter/Manifold
Assembly (Page 27,28,29).
5. Assemble the Charge Pump Assembly
(Page 27).
6. Assemble the Auxialiary Pump Assembly
(Page 26)
7. Assemble the Input Shaft Assembly (Page
25).
8. Assemble the Fan and Pulley Assembly
(Page 24).
9. Assemble the Torque Bracket Assembly
(Page 23).
10. Assemble the Control Arm Assembly (Page
20,21).
11. Assemble the Bypass Assembly (Page
19).
12. Assemble the Brake Assembly (Page
17,18).
38
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-1500/-1700 IHT
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SEALANT APPLICATION
NOTE: Prior to applying the new sealant,
the old sealant must be removed from
all surfaces.
A small consistent bead of the sealant around
the housing face will be sufficient. Use sparingly.
The illustration below illustrates the correct
areas.
Figure 29.
Figure 30.
-1500/-1700 IHT
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39
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
Figure 31. IHT -1500 Exploded View
40
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-1500/-1700 IHT
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
ITEMS LIST -1500
Part numbers are not provided in this manual. See CD (BLN-51427) for part numbers.
NO.
1
2A
2B
3
4
5
6
7
8
10
11
12
13
14
15
21
24
25
26
27
28
30
31
32
33
34
35
36
38
39
40
41
42
43
44
46
48
50
51
55
57
58
59
60
61
62
63
64
65
66
67
68
69
71
73
74
75
DESCRIPTION
Main Housing Assembly
R.H. Housing Assembly
Brake Bolt Kit
Center Section Assembly
Spacer
Lip Seal
Wire Retaining Ring
Retaining Ring
Ball Bearing
Variable Swashplate
Thrust Bearing
Input Shaft
Block Thrust Washer
Block Spring
10cc Cylinder Block Assembly
21cc Cylinder Block Assembly
Output (Motor) Shaft
Thrust Bearing
Control Arm
Spacer
19T Pinion Gear
Slot Guide
Trunnion Arm
Trunnion Bushing
Lip Seal
Return Arm
Actuating Arm
Stud 5/16 - 24
Bypass Plate
Bypass Actuator
Lip Seal
Bypass Arm
Retaining Ring
Pin
Screw
Neutral Spring
Adjusting Puck
Screw , Self-Tapping
Lower Cover
Filter Kit
Retainer, Motor Bearing
Pin, Carrier
15T Planet Gear
67T Spur Gear
21T Sun Gear
Planet Thrust Plate
51T Ring Gear
Planetary Carrier
Miter Gear, Differential (SPLINED)
Miter Gear, Differential
Shaft , Differential
Differential Thrust Plate
Flange Bearing
Washer
Hex Jam Nut, 5/8 - 18
Ball Bearing 6205-1
Seal, 1” ID X 2.0472” X 0.375”
-1500/-1700 IHT
NO.
76
77
79
80
81
82
83
84
85
86
87
88
89
90
92
93
94
95
96
97
102
103
104
106
107
109
110
111
113
115
116
117
118
119
120
121
122
124
125
128
129
130
131
132
133
141
142
143
151
153
155
157
168
180
203
210
DESCRIPTION
Shaft, Axle
Washer
Gasket Material/Sealant
Torx Head Screw 5/16 - 18
Needle Bearing
Washer
Retaining Ring
Lip Seal
Brake Disc
Washer
Washer
Screw 5/16 - 24 X 1-3/4
Bearing
Spacer, Locating
Countersunk Screw
Spring Spacer
Spacer
Nut, Hex Lock 5/16 - 24
Sleeve Bearing
20W50 Oil
Torque Bracket
Pulley
Fan
Spacer, Trunnion
Screw
Vent Bushing
Fitting Kit
Cap-Vent Assembly
Hose/ Fitting Assembly
Jam Nut
Retaining Ring
Std Hlds Pins
Hub Assembly 7/16 - 14
Nut, Hex 3/4 - 16
Puck, Brake
Bolt, 1/4 - 20 X 1.25
Brake Yoke
Arm, Brake
Pins, Brake
Nut, Castle
Cotter Pin
Spacer
Puck Plate
Bolt, 1/4 - 20 X 2.25
Wheel Stud 7/16-14
Spring, Brake Arm Bias
Hex Lock Nut 5/16 - 18
Bolt 5/16 -15 X 2.5
Compression Spring Brake Anti-Drag
Plug, Straight Thread
Fan/ Pulley Assembly
Screw O-Ring
Screw, Shoulder Torx Head
Manifold Kit
Seal Kit (310-3000)
Nut, Lug
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41
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
Figure 32. IHT -1700 Exploded View
42
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-1500/-1700 IHT
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
ITEMS LIST -1700
Part numbers are not provided in this manual. See CD (BLN-51427) for part numbers.
NO.
1
2A
2B
3
4
5
6
7
8
10
11
12
13
14
15
21
24
25
26
27
28
30
31
32
33
34
35
36
38
39
40
41
42
43
44
46
48
49
50
51
52
53
54
55
57
58
59
60
61
62
63
64
65
66
67
68
69
71
73
74
75
76
77
79
80
81
82
83
84
85
DESCRIPTION
Main Housing Assembly
R.H. Housing Assembly
Brake Bolt Kit
Center Section Assembly
Spacer
Lip Seal
Wire Retaining Ring
Retaining Ring
Ball Bearing
Variable Swashplate
Thrust Bearing
Input Shaft
Block Thrust Washer
Block Spring
10cc Cylinder Block Assembly
21cc Cylinder Block Assembly
Output (Motor) Shaft
Thrust Bearing
Control Arm
Spacer
19T Pinion Gear
Slot Guide
Trunnion Arm
Trunnion Bushing
Lip Seal
Return Arm
Actuating Arm
Stud 5/16 - 24
Bypass Plate
Bypass Actuator
Lip Seal
Bypass Arm
Retaining Ring
Pin
Screw
Neutral Spring
Adjusting Puck
Auxiliary Charge Pump Kit
Screw , Self-Tapping
Lower Cover
Gerotor Assembly
O-Ring
Auxiliary Manifold Kit
Filter Kit
Retainer, Motor Bearing
Pin, Carrier
15T Planet Gear
67T Spur Gear
21T Sun Gear
Planet Thrust Plate
51T Ring Gear
Planetary Carrier
Miter Gear, Differential (SPLINED)
Miter Gear, Differential
Shaft , Differential
Differential Thrust Plate
Flange Bearing
Washer
Hex Jam Nut, 5/8 - 18
Ball Bearing 6205-1
Seal, 1” ID X 2.0472” X 0.375”
Shaft, Axle
Washer
Gasket Material/Sealant
Torx Head Screw 5/16 - 18
Needle Bearing
Washer
Retaining Ring
Lip Seal
Brake Disc
-1500/-1700 IHT
NO.
DESCRIPTION
86
87
88
89
90
92
95
96
97
102
103
104
106
107
108
109
110
111
113
115
116
117
118
119
120
121
122
124
125
128
129
130
131
132
133
139
141
142
143
145
146
151
153
155
157
162
163
164
165
166
167
168
170
171
172
173
175
177
178
179
180
181
182
183
184
203
208
209
210
Washer
Washer
Screw 5/16 - 24 X 1-3/4
Bearing
Spacer, Locating
Countersunk Screw
Nut, Hex Lock 5/16 - 24
Sleeve Bearing
20W50 Oil
Torque Bracket
Pulley
Fan
Spacer, Trunnion
Screw
Plug
Vent Bushing
Fitting Kit
Cap-Vent Assembly
Hose/ Fitting Assembly
Jam Nut
Retaining Ring
Std Hlds Pins
Hub Assembly 7/16 - 14
Nut, Hex 3/4 - 16
Puck, Brake
Bolt, 1/4 - 20 X 1.25
Brake Yoke
Arm, Brake
Pins, Brake
Nut, Castle
Cotter Pin
Spacer
Puck Plate
Bolt, 1/4 - 20 X 2.25
Wheel Stud 7/16-14
Washer
Spring, Brake Arm Bias
Hex Lock Nut 5/16 - 18
Bolt 5/16 -15 X 2.5
Relief Spring
Ball
Compression Spring Brake Anti-Drag
Plug, Straight Thread
Fan/ Pulley Assembly
Screw O-Ring
Shim
Pin
Valve Body
O-Ring
Spring
Ball
Screw, Shoulder Torx Head
Cam, Stationary
Cam, Rotating
Washer
Load Plate
Dog, Engagement
Washer Guide
Cam, Actuating
Shaft
Sleeve
Handle, Actuating
Ring, Retaining
O-Ring
O-Ring
Seal Kit
Auxiliary Relief Valve Kit
Charge Relief Kit
Nut, Lug
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43
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
SECTION 6. GLOSSARY OF TERMS
Axial Piston: Type of design for hydraulic motors and pumps in which the pistons are arranged
parallel with the spindle (input or output shaft).
Bypass Valve: A valve whose primary function is to open a path for the fluid to bypass the motor
or pump. Also referred to occasionally as the freewheel valve or dump valve.
Case Drain Line (Return Line): A line returning fluid from the component housing to the reservoir.
Cavitation: A concentrated gaseous condition within the fluid causing the rapid implosion of a
gaseous bubble.
Center Section: A device which acts as the valve body and manifold of the transmission.
Charge Pump: A device which supplies replenishing fluid to the fluid power system (closed
loop).
Charge Pressure: The pressure at which replenishing fluid is forced into a fluid power system.
Charge Relief Valve: A pressure control valve whose primary function is to limit pressure in the
charge circuit.
Check Valve: A valve whose primary function is to restrict flow in one direction.
Closed Loop: A sealed and uninterrupted circulating path for fluid flow from the pump to the
motor and back.
Decay Rate: The ratio of pressure decay over time.
End Cap: See “Center Section”
Entrained Air: A mechanical mixture of air bubbles having a tendency to separate from the liquid
phase.
Gerotor: A positive displacement pump frequently used as a charge pump.
Hydraulic Motor: A device which converts hydraulic fluid power into mechanical force and motion by transfer of flow under pressure.
Hydraulic Pump: A device which converts mechanical force and motion into hydraulic fluid power
by producing flow.
Hydrostatic Pump: See “Hydraulic Pump”
44
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Hydrostatic Transaxle: A multicomponent assembly including a gear case and a hydrostatic
transmission.
Hydrostatic Transmission: The combination of a hydraulic pump and motor in one housing to
form a device for the control and transference of power.
Inlet Line: A supply line to the pump.
Integrated Hydrostatic Transaxle (IHT): The combination of a hydrostatic transmission and
gear case in one housing to form a complete transaxle.
Manifold: A conductor which provides multiple connection ports.
Neutral: Typically described as a condition in which fluid flow and system pressure is below that
which is required to turn the output shaft of the motor.
Pressure Decay: A falling pressure.
Priming: The filling of the charge circuit and closed loop of the fluid power system during start
up, frequently achieved by pressurizing the fluid in the inlet line.
Purging: The act of replacing air with fluid in a fluid power system by forcing fluid into all of the
components and allowing the air a path of escape.
Rated Flow: The maximum flow that the power supply system is capable of maintaining at a
specific operating pressure.
Scoring: Scratches in the direction of motion of mechanical parts caused by abrasive contaminants.
Swash Plate: A mechanical device used to control the displacement of the pump pistons in a
fluid power system.
System Charge Check Valve: A valve controlling the replenishing flow of fluid from a charge
circuit to the closed loop in a fluid power system.
System Pressure: The pressure which overcomes the total resistance in a system, including
all losses.
Valve: A device which controls fluid flow direction, pressure, or flow rate.
Variable Displacement Pump: A pump in which the displacement per cycle can be varied.
Volumetric Displacement: The volume for one revolution.
-1500/-1700 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
© 2008 HYDRO-GEAR
Printed in U.S.A.
Rev. P1
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