Page 1
HYDRO-GEAR 310-3000 INTEGRATED HYDROSTATIC TRANSAXLE SERV MANL
Table of Contents – Page 1 of 2
FOREWORD
DESCRIPTION AND OPERATION
INTRODUCTION
GENERAL DESCRIPTION
INTRODUCTION
HYDRAULIC SCHEMATIC
TECHNICAL SPECIFICATIONS
PRODUCT IDENTIFICATION
SAFETY
PERSONAL SAFETY
TOOL SAFETY
WORK AREA SAFETY
SERVICING SAFETY
TROUBLESHOOTING
SERVICE AND MAINTENANCE
EXTERNAL MAINTENANCE
SERVICE AND MAINTENANCE PROCEDURES
FLUIDS
BRAKE MAINTENANCE
RETURN TO NEUTRAL SETTING HAND CONTROL
RETURN TO NEUTRAL SETTING FOOT CONTROL
PURGING PROCEDURES
REPAIR
GENERAL INSTRUCTIONS
REQUIRED TOOLS
TORQUE SPECIFICATIONS
TRANSAXLE REMOVAL
LIMITED DISASSEMBLY
HOW TO USE THIS MANUAL
BRAKE ASSEMBLY
BYPASS ASSEMBLY
CONTROL ARM ASSEMBLY
TORQUE BRACKET ASSEMBLY
FAN AND PULLEY ASSEMBLY
INPUT SHAFT ASSEMBLY
CHARGE PUMP ASSEMBLY
LOWER HOUSING/FILTER/MANIFOLD ASSEMBLY
PLANETARY DIFFERENTIAL ASSEMBLY
MOTOR/CENTER SECTION/PUMP ASSEMBLY
Page 2
HYDRO-GEAR 310-3000 INTEGRATED HYDROSTATIC TRANSAXLE SERV MANL
Table of Contents – Page 2 of 2
REPAIR - Continued
DIRECTIONAL CONTROL ASSEMBLY
TRANSAXLE INSTALLATION
ASSEMBLY AFTER A COMPLETE TEAR-DOWN
PARTS LIST
GLOSSARY OF TERMS
Page 3
Table of Contents
Section Page
Foreword.............................................................................................................................. i
Description and Operation................................................................................................. 1
Introduction ........................................................................................................................ 1
General Description................................................................................................................................. 1
Introduction ............................................................................................................................................. 1
Hydraulic Schematic................................................................................................................................ 2
Technical Specifications........................................................................................................................... 3
Product Identification ............................................................................................................................... 3
Safety .................................................................................................................................. 4
Personal Safety....................................................................................................................................... 4
Tool Safety .............................................................................................................................................. 4
Work Area Safety .................................................................................................................................... 4
Servicing Safety....................................................................................................................................... 4
Troubleshooting................................................................................................................. 5
Service and Maintenance................................................................................................... 6
External Maintenance.............................................................................................................................. 6
Service and Maintenance Procedures....................................................................................................... 6
Fluids...................................................................................................................................................... 7
Brake Maintenance.................................................................................................................................. 8
Return to Neutral Setting Hand Control..................................................................................................... 9
Return to Neutral Setting Foot Control.................................................................................................... 10
Purging Procedures`............................................................................................................................... 11
Repair ................................................................................................................................ 12
General Instructions............................................................................................................................... 12
Required Tools....................................................................................................................................... 12
Torque Specifications............................................................................................................................. 12
Transaxle Removal ................................................................................................................................ 12
Limited Disassembly ............................................................................................................................. 12
How to Use This Manual........................................................................................................................ 13
Brake Assembly ................................................................................................................................ 14,15
Bypass Assembly.................................................................................................................................. 16
Control Arm Assembly ....................................................................................................................... 17,18
Torque Bracket Assembly ...................................................................................................................... 19
Fan and Pulley Assembly ...................................................................................................................... 20
Input Shaft Assembly............................................................................................................................. 21
Charge Pump Assembly ........................................................................................................................ 22
Lower Housing/Filter/Manifold Assembly................................................................................................. 23
Planetary Differential Assembly.......................................................................................................... 24,25
Motor/Center Section/Pump Assembly .......................................................................................... 26,27,28
Directional Control Assembly ................................................................................................................. 29
Transaxle Installation............................................................................................................................. 30
Assembly After a Complete Tear-down.................................................................................................... 30
Parts List ...................................................................................................................... 31,32
Glossary of Terms ....................................................................................................... 33,34
Page 4
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 the 3103000Hydro-Gear Integrated Hydrostatic
Transaxle (IHT). The Troubleshooting Guide order number is BLN-51095.
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 good shop practice, that your
service area be equipped with proper tools and
the mechanics to be supplied with the latest information available. All repair procedures
illustrated in this guide are suggested, but preferred methods of repair.
Repair procedures require that the transaxle unit
be removed from the vehicle.
Some cleaning solvents are flammable. To avoid
possible fire, do not use cleaning solvents in an
area where a source of ignition may be present.
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 OPE Technicians Certification of Austin, Texas or their 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 one of our Central Service Distributors, or call our Technical Service
Department at (217) 728-2581.
310-3000 IHT
i
Page 5
SECTION 1. DESCRIPTION AND OPERATION
INTRODUCTION
The purpose of this manual is to provide information useful in servicing the Hydro-Gear 3103000 Integrated Hydrostatic Transaxle (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 310-3000 is a self contained unit designed
for the transfer and control of power. It provides
an infinitely variable speed range between zero
and maximum in both forward and reverse
modes of operation.
This 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 swashplate re-
verses 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 310-3000 has 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
310-3000 to permit moving the vehicle for short
distance at a maximum of 2 m.p.h. 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 310-3000 utilizes an in-line floating disc
brake controlled by a "cam" style actuating arm.
310-3000 IHT 1
Page 6
Figure 1. 310-3000 Hydraulic Schematic
HYDRAULIC SCHEMATIC
Figure 1 provides an illustration of the hydraulic
oil circuit. The oil supply for the hydraulic system
of the 310-3000 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 310-3000
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
310-3000 IHT
2
Page 7
discharged through the charge relief valve. The
charge relief valve maintains the charge pressure at no more than 40 PSI.
The motor cylinder block mounts onto the splined
motor shaft which drives the planetary differential gear/differential assembly.
The bypass feature in the 310-3000 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.
TECHNICAL
SPECIFICATIONS
Technical specifications for the 310-3000 IHT are
given in Table 1.
PRODUCT IDENTIFICATION
Table 1. 310-3000 Technical Specifications
Overall Transaxle Reduction
30.15:1
Input Speeds
Maximum: 3600 RPM
Minimum: 1800 RPM
Maximum Tire Diameter
23 inch; 584 mm
Axle Shaft Options
Type: Keyed
Diameter: 1 inch; 25.4 mm
Type: Flanged
Diameter: Hub
Brake Type
Disc
The model and configuration of the 310-3000 IHT
can be determined from the label shown in Figure 2.
H Y D R O - G E A R
SULLIVAN, IL. U.S.A.
I IIII III I III II II
OEM Model
Number
165758 310-3000
I II IIII IIII III III I II IIII
8 328 T1 476 Made in U.S.A.
Year Built
(unique number for that model - for that day)
Weight of Unit
58 lb; 26 kg
Hydro-Gear
Number
Serial Number
Date
(Julian - day of year)
Type of Product and Build Information
Figure 2. 310-3000 Configuration Label
310-3000 IHT 3
Page 8
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
310-3000 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 310-3000 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:
Other manuals pertaining to this machine
Local and shop safety rules and codes
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.
Wear appropriate clothing. Loose or
hangingclothing 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.
310-3000 IHT
4
Page 9
SECTION 3. TROUBLESHOOTING
WARNING
Do not attempt any servicing or adjustments with the engine running.
Use extreme caution while inspecting the
drive belt assembly, and all vehicle linkage!
Follow all safety procedures outlined in
the vehicle owner’s manual!
Table 2. 310-3000 Troubleshooting Checklist
Possible Cause
UNIT OPERATES IN ONE DIRECTION ONLY
Control linkage bent or out of adjustment
Drive belt slipping or pulley damaged
Oil level low or contaminated oil
Excessive loading
Brake setting incorrect
Loose parts
Bypass assembly sticking
Air trapped in hydraulic system
Repair or replace linkage
Repair or replace drive belt or pulley
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
Corrective Action Refer To:
UNIT IS NOISY
In many cases problems with the 310-3000 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.
Control Linkage Repair, Page 17
Pulley Repair, Page 20
Fluid Maintenance, Page 7
Vehicle Specifications
Brake Adjustment, Page 8
Appropriate Repair Procedure
Bypass Repair, Page 16
Purging Procedure, Page 11
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
Debris buildup around transaxle
Brake setting incorrect
Cooling fan damaged
Oil level low or contaminated oil
Excessive loading
Air trapped in hydraulic system
Damaged seals, housing, or gaskets
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
UNIT OPERATING HOT
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
TRANSAXLE LEAKS OIL
Replace damaged component
Purge hydraulic system
Vehicle Specifications
Control Linkage Repair, Page 17
Brake Adjustment, Page 8
Pulley Repair, Page 20
Fluid Maintenance, Page 7
Vehicle Specifications
Bypass Repair, Page 16
Purging Procedure, Page 11
Brake Adjustment, Page 8
Cooling Fan Repair, Page 20
Fluid Maintenance, Page 7
Vehicle Specifications Purging
Procedure, Page 11
Appropriate Repair Procedure
Purging Procedure, Page 11
310-3000 IHT 5
Page 10
SECTION 4. SERVICE AND MAINTENANCE
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.
EXTERNAL MAINTENANCE
Reference Table 4., Page 13 for tools required
in the maintenance of the 310-3000 IHT.
Regular external maintenance of the 310-3000
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 3, Page 7.
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 RPM to the transaxle
4. Inspect the transaxle cooling fan for broken
or distorted blades and remove any obstructions (grass clippings, leaves dirt, etc.).
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 310-3000 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.
310-3000 IHT
6
Page 11
FLUIDS
FLUID CHANGE
The fluids used in Hydro-Gear products have been
carefully selected, and only equivalent, or better
products should be substituted.
Typically, an engine oil with a minimum rating of
55 SUS at 210 F and an API classification of
SH/ 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 11.
This transaxle is factory filled and does not require regular oil change. In the event of oil contamination or degradation an oil change may
improve performance.
Using transaxle removal procedure from Section
5, Page 12, remove transaxle and drain oil from
top fluid fill port. Fill unit per Table 3, reinstall
transaxle and perform purging procedures, Page
11.
In the event fluid change and filter inspection is
required, refer to Page 23, 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.
Table 3. Fluid Volumes for the 310-3000 IHT
Fluid Description
20W-50 engine oil
Figure 3. 310-3000 Fluid Fill and Level Ports
Volume
0.95 gal . (116.5 oz.)
310-3000 IHT 7
Page 12
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" feeler gage between the brake
disc and top brake puck, and then set the
brake by tightening or loosening the castle
nut.
RETURN TO NEUTRAL SETTING
(OPTIONAL FEATURE)
The return to neutral mechanism on the transmission is designed to set the directional control
into a neutral position. An optional feature, it is
available in two versions. One version provides
hand control, and the other, foot control. Setting
procedures are provided on pages 9 and 10.
WARNING
3. Adjust brake gap to 0.015" clearance.
4. Install the cotter pin to secure the castle nut,
and then install the brake arm bias spring.
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.
310-3000 IHT
8
Page 13
RETURN TO NEUTRAL SETTING
HAND CONTROL
4. Apply the vehicle brake, start the engine and
increase the throttle to full engine rpm.
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 vehicle parking brake is engaged. 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.
2. Remove the Original Equipment
Manufacturer’s (OEM’s) control linkage at
the control arm. Refer to Figure 4.
5. Check for axle rotation. If the axles do not rotate, go to Step 6. If the axles rotate, go to
Step 7.
6. Stop the vehicle engine. Adjust the OEM linkage according to the OEM manual. Recheck
according to step 4 and 5. Stop the vehicle
engine. Replace the brake pull rod onto the
return actuating arm. Install the washer and
a new cotter pin securing the brake pull rod
to the actuating arm. Refer to Figure 4.
7. Note the axle directional movement . Stop
the vehicle’s 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 13. Recheck
according to step 4 and 5. Stop the vehicle
engine. Adjust the OEM linkage according
to the OEM manual. Recheck according to
Step 4 and 5. Stop the vehicle engine. Replace the brake pull rod onto the return actuating arm. Install the washer and a new cotter pin securing the brake pull rod to the actuating arm. Refer to Figure 4.
3. Remove the cotter pin and washer securing
the brake pull rod to the return actuating arm.
Remove the brake pull rod from the return
actuating arm. Refer to Figure 4.
WARNING
Do not attempt any adjustments with the
engine running. Use extreme caution
while inspecting all vehicle linkage!
Follow all safety procedures outlined in
the vehicle owner’s manual!
Figure 4. Return to Neutral, Hand Control
310-3000 IHT 9
Page 14
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.
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 5.
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 13. 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 5.
NOTE: It may be necessary to remove
the drive tire from the axle hub to access
the linkage control and the transaxle control arm.
2. Remove the Original Equipment
Manufacturer’s (OEM’s) control linkage at the
control arm. Refer to Figure 5.
WARNING
Do not attempt any adjustments with the
engine running. Use extreme caution
while inspecting all vehicle linkage!
Follow all safety procedures outlined in
the vehicle owner’s manual!
Figure 5. Return to Neutral, Foot Control
310-3000 IHT
10
Page 15
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.
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 and bubbles may appear in the
oil. After stopping the engine, add oil, as necessary. Fill to the level outlined in Figure 3,
Page 7.
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, purging is complete.
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 level
shown in figure 3, Page 7. This will allow
the space needed for the oil to expand
as it warms up.
310-3000 IHT 11
Page 16
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 3103000 IHT is provided in Table 4, Page 13.
TORQUE SPECIFICA TIONS
Torque specifications for fasteners used on
the310-3000 IHT are provided in Table 5.
TRANSAXLE REMOVAL
It is necessary to remove the 310-3000 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 19) Page 31, retaining
the hub (118, Figure 19) 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 30.
310-3000 IHT
12
Page 17
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.
Table 4. Required Tools
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.
Miscellaneous
310-3000 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
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"
Table 5. Required Torque Values
Operation Torque Item #Part Description
Center Section Screws (Item #4) 525-700 lb-in 44 Screw
Lower Housing Screws (Item # 50) 135-185 lb-in 50 Screw
Charge Pump Cover Screws (Item # 29) 87-108 lb-in 29 M6 x 1-22
Axle Shaft Jam Nut (Item # 73) 660-800 lb-in 73 5/16-18
Right Hand Housing Screws (Item # 80) 230-290 lb-in 80 5/16-18
Axle Hub Nut (Item # 119) 200-295 lb-ft 119 3/4-16
Pulley Nut (Item # 115) 360-520 lb-ft 115 Jam Nut
Fan Screws (Item # 107) 35-50 lb-in 107 Screw
Bypass Screw (Item # 138) 42-62 lb-in 138 10-32 x 1/2
Torque Bracket Nut (Item # 142) 160-210 lb-in 142 5/16-18
Control Arm Stud (Item # 36) 50-120 lb-in 36 5/16-24
Trunnion Shaft Nut (Item # 95) 180-240 lb-in 95 5/16-24
Control Bearing Screw (Item # 92) 190-240 lb-in 92 Screw
Control Arm Nut (Item # 95) 85-120 lb-in 95 5/16-24
Adjusting Puck Screw (Item # 88) 250-320 lb-in 88 5/16-24 x 1-3/4
Brake Nuts (Item # 127) 80-120 lb-in
127 1/4-20
310-3000 IHT 13
Page 18
BRAKE ASSEMBLY
Refer to Figures 6 and 7.
DISASSEMBLY
4. Remove the cotter pin (129), castle nut (128),
and washer (77).
5. Remove brake arm (124), and brake arm
bias spring (141).
The following procedure is for model 324-3000.
Reference microfiche for other models.
1. Remove lock nut (95), washer (77), brake
spring (134), and washer (77) from brake pull
rod (152).
2. Remove cotter pin (129), and washer (77)
from brake pull rod (152).
3. Remove brake pull rod (152) and set aside.
6. Remove brake anti-drag compression spring
(151), and two brake pins (125).
7. Remove upper nut (127), lock washer (126),
washer (139), and spacer (130) which secure
brake yoke assembly (122).
8. Remove lower nut (127), and lock washer
(126) securing brake yoke assembly (122).
9. Remove brake yoke assembly (122), puck
plate (131), and outer brake puck (120).
10.Remove brake disc (85), and inner brake
puck (120).
310-3000 IHT
REF. Part Name
2 Right Hand Housing Assembly
77 Washer
85 Brake Disk
95 Lock Nut
120 Brake Puck
122 Brake Yoke Assembly
123 Square Head Bolt
124 Brake Arm
125 Brake Pin
126 Lock Washer
Figure 6. Brake Assembly
REF. Part Name
127 Nut
128 Castle Nut
129 Cotter Pin
130 Spacer
131 Puck Plate
134 Brake Spring
139 Washer
141 Brake Arm Bias Spring
151 Anti-Drag Compression Spring
152 Brake Pull Rod
14
Page 19
INSPECTION
1. Inspect the brake pucks (120) for excessive
wear.
7. Install brake arm (124) onto brake yoke assembly.
8. Install washer (77), and castle nut (128).
2. Replace with new if necessary.
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. Install the brake yoke assembly onto two
mounting studs on housing assembly (2). Use
of a feeler gage (0.015”) may be helpful in
retaining the brake yoke assembly at this
step.
4. Install at upper bolt spacer (130), washer
(139), lock washer (126), and nut (127).
5. Install at lower bolt lock washer (126), and
nut (127) to secure the brake yoke assembly.
9. Insert a (0.015”) feeler gage between brake
disc (85) and top 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”)
clearance.
10.Install cotter pin (129) to secure castle nut
(128).
11.Install brake arm bias spring (141) to brake
arm (124) and top brake arm bolt.
12.Install brake pull rod (152) into brake arm
(124) and actuating arm (35).
13.Secure brake rod (152) to actuating arm (35)
by installing washer (77) and cotter pin (129).
14.Secure brake pull rod (152) to brake arm by
installing washer (77), brake spring (134),
washer (77), and lock nut (95). Set to the dimension shown in Figure 7.
6. Install brake anti-drag compression spring
(151), and two brake pins (125).
Figure 7. Brake Pull Rod Assembly Adjustment
310-3000 IHT 15
Page 20
BYPASS ASSEMBLY
42
Refer to Figure 8.
DISASSEMBLY
41
40
137
1. Remove self tapping screw (138), and extension spring (136).
2. Remove snap ring (42), and bypass arm (41).
3. Remove bypass lip seal (40).
INSPECTION
1. Inspect spring pin (137) for damage.
ASSEMBLY
1. If necessary, install new spring pin (137).
2. Install bypass lip seal (40).
3. Install bypass arm (41), and snap ring (42).
4. Install self tapping screw (138), and extension spring (136).
138
136
1
REF. Part Name
1 Main Housing
40 Lip Seal
41 Bypass Arm
42 Retaining Ring
136 Spring
137 Spring Pin
138 Screw
Figure 8. Bypass Assembly
310-3000 IHT
16
Page 21
CONTROL ARM ASSEMBLY
Refer to Figure 9, Page 18
DISASSEMBLY
NEUTRAL ASSEMBLY
NOTE: The brake pull rod (152), washer
(77), and cotter pin (129) must be removed before disassembling the Neutral
Assembly (refer to Brake Assembly).
1. Remove bolt (88) and adjusting puck (48).
2. Remove neutral spring (46), actuating arm
(35), return arm (34), and washer (87).
CONTROL ARM ASSEMBLY
1. Remove upper lock nut (95), washer (77),
spring (93), spacer (94), washer (77), and
friction puck (37).
2. Remove lower lock nut (95), and trunnion
spacer (106), from the trunnion arm (31).
3. Remove control arm (26).
4. Remove friction puck (37), and stud (36), if
necessary.
INSPECTION
2. Inspect trunnion arm lip seal (33), and replace
if necessary.
ASSEMBLY
CONTROL ARM ASSEMBLY
1. Install trunnion arm lip seal (33), into main
housing (1).
2. Install stud (36), per Table 5, Page 16 and
friction puck (37).
3. Install control arm (26), onto trunnion arm (31),
and stud (36), with washer (77) and nut (95)
per Table 5, Page 13.
NOTE: If bearing (89) must be replaced,
install bearing (89), washer (90), and
countersink screw (92).
4. Install friction puck (37), washer (77), spring
(93), spacer (94), washer (77), and lock nut
(95). Tighten locknut to (120 in. lbs.), then
back off (1) full turn.
NEUTRAL ASSEMBL Y
1. Install washer (87), return arm (34), actuating
arm (35), and neutral spring (46).
2. Install adjusting puck (48), and bolt (88).
1. Inspect bearing (89), and replace if necessary. Remove bearing by removing countersink screw (92), and washer (90).
3. Reference Pages 9, 10 for proper neutral
adjustment procedures.
310-3000 IHT 17
Page 22
31328734354648
88
36
268990923777939477
9533106
37
95
REF. Part Name
26 Control Arm
31 Trunnion Arm
32 Trunnion Bushing
33 Trunnion Arm Lip Seal
34 Return Arm
35 Actuating Arm
36 Stud
37 Friction Puck
46 Spring
48 Adjusting Puck
Figure 9 Control Arm Assembly
REF. Part Name
77 Washer
87 Washer
88 Screw
89 Bearing
90 Locating Spacer
92 Countersink Screw
93 Spring
94 Spacer
95 Locknut
106 Trunnion Spacer
310-3000 IHT
18
Page 23
TORQUE BRACKET
102
142
143
ASSEMBLY
Refer to Figure 10.
DISASSEMBLY
1. Remove lock nut (142), and bolt (143), from
torque bracket (102).
2. Remove torque bracket (102), from main
housing (1).
ASSEMBLY
143
102
142
1
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 13 for torque
values.
REF. Part Name
1 Main Housing
102 Torque Bracket
142 Lock Nut
143 Bolt
Figure 10. Torque Bracket Assembly
310-3000 IHT 19
Page 24
FAN AND PULLEY
107
115
10312104
ASSEMBLY
Refer to Figure 11.
DISASSEMBLY
1. Remove jam nut (115) from input shaft (12).
2. Remove fan/pulley assembly (104), (103),
(107).
INSPECTION
1. Inspect fan (104) for broken and/or damaged
blades. If necessary to replace fan (104), remove screws (107), and fan (104), from pulley (103).
ASSEMBLY
1. Install fan/pulley assembly (104), (103), (107)
onto input shaft (12).
2. Secure fan/pulley assembly (104), (103),
(107) onto shaft (12) by installing jam nut
(115), per table 5, Page 13.
107
104
103
12
1
REF. Part Name
1 Main Housing
12 Input Shaft
103 Pulley
104 Fan
107 Screw
115 Jam Nut
Figure 11. Fan and Pulley Assembly
310-3000 IHT
20
Page 25
INPUT SHAFT ASSEMBLY
75468
12
Refer to Figure 12.
DISASSEMBLY
1. Drain the oil from the transaxle.
2. Remove snap ring (7), input shaft lip seal (5),
and spacer (4).
REF. Part Name
1 Main Housing
4 Spacer
5 Lip Seal
6 Wire Retaining Ring
7 Snap Ring
8 Ball Bearing
12 Input Shaft
13 Block Thrust Washer
7
5
4
6
8
3. Remove input shaft assembly (12), (8), (6).
4. Remove washer (13) from cavity.
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 cavity.
2. Press bearing (8) onto input shaft (12) and
secure by installing wire retaining ring (6).
3. Install input shaft assembly (12), spacer (4),
and lip seal (5) into input bearing bore of main
housing (1).
12
1
Figure 12. Input Shaft Assembly
4. Secure input shaft assembly (12) by installing retaining ring (7).
310-3000 IHT 21
Page 26
525354
CHARGE PUMP ASSEMBLY
Refer to Figure 13.
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
1. Remove two screws (29) from the charge
pump cover (54), and remove charge pump
cover (54).
2. Remove o-ring (53) and gerotor assembly
(52).
INSPECTION
1. Inspect gerotor assembly (52), cavity of
charge pump cover (54), plate on which cover
is mounted for damage or excessive wear.
ASSEMBLY
1. Install gerotor assembly (52) onto input shaft
(12) (not shown).
2. Install new O-ring (53) into charge pump cover
(54).
3. Install charge pump cover (54), making sure
it is properly oriented.
REF. Part Name
1 Main Housing
29 Screw
52 Gerotor Assembly
53 O-ring
54 Gerotor Cover
Figure 13. Charge Pump Assembly
29
52
53
54
4. Secure charge pump cover (54) by installing
two screws (29), per Table 5, Page 13.
310-3000 IHT
22
Page 27
LOWER HOUSING/FILTER/
144561575551, 79
525354
29
MANIFOLD ASSEMBLY
Refer to Figure 14.
NOTE: Charge Pump assembly must be
removed before the following steps can
be performed.
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.
2. Inspect o-ring (144) and screw O-rings (157).
ASSEMBLY
1
50
1. Install o-ring (144) onto center section assembly (3), refer to Figure 134
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).
7. Reinstall cover (51) and screws (29), reference Table 5, Page 13.
8. Secure lower cover (51) to main housing (1)
by installing the eleven housing screws (50),
reference Table 5, Page 13.
REF. Part Name
1 Main Housing
29 Capscrew
49 Not Used
50 Screws
51 Lower Cover
52 Gerotor Assembly
53 O-Ring
54 Gerotor Cover
Figure 14. Lower Housing/Filter/Manifold Assembly
REF. Part Name
55 Filter
56 Charge Manifold
144 O-Ring
145 Spring
146 Ball
156 Manifold O-Ring
157 Screw O-Ring
310-3000 IHT 23
Page 28
PLANETARY DIFFERENTIAL
ASSEMBLY
2. Remove all sealant from both housings and
inspect seal lands for damage when cleaning.
Refer to Figure 15, 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) that
secure the R.H. housing assembly (2).
3. Remove R.H. housing assembly (2), while
holding axle shaft (76) in place.
4. Remove the two housing pins (117).
5. Remove washer (71) from axle shaft (76).
6. Remove spur gear (60), and thrust plate (62).
3. If miter gear (65) needs replaced, 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 (70), miter 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 miter gears (66) onto
differential shaft (67), and install assembly into
planetary carrier (64).
5. Install 51T ring gear (63) into main housing
(1).
7. Remove 21T sun gear (61), and sleeve bearing (96).
8. Remove the planetary gears (59).
9. Remove washer (70), and axle shaft (76).
10.Remove the four carrier pins (58) from planetary carrier (64).
11.Remove 51T ring gear (63) from main housing (1).
12.Remove the two miter gears (66), and differential shaft (67).
13.Remove planetary carrier (64) and differential thrust plate (68).
14.If necessary, remove the second axle shaft
assembly (76) from main housing (1).
15.Remove the seal from the shaft, if necessary.
INSPECTION
1. Inspect all gears for excessive wear or damage and replace if necessary.
6. Install the four carrier pins (58) into planetary
carrier (64).
7. If necessary, reassemble axle shaft assembly (76) by installing washer (70), miter gear
(65), and jam nut (73) onto axle shaft (76).
8. 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 9 through 16 are
completed.
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”.
10.Install the four 15T planetary gears (59) on
pins (80) . Make sure the planetary gears are
properly aligned with the sun gear. Mate the
bevel gear on the end of the RH axle shaft
with the bevel gears in the differential assembly. Continue to support the RH axle shaft.
310-3000 IHT
24
Page 29
73
616260
712118
119
119
117
118
65
76
70
D
C
B
A
59
1
70
76
96
80
REF. Part Name
1 Main Housing
2 R.H. Housing Assembly
58 Carrier Pin
59 Planetary Gears
60 67t Spur Gear
61 21t Sun Gear
62 Planetary Thrust Plate
63 51t Ring Gear
64 Planetary Carrier
65 Differential Miter Gear
66 Differential Miter Gear
67 Differential Shaft
68 Differential Thrust Plate
REF. Part Name
70 Washer
71 Washer
63 51t Ring Gear
64 Planetary Carrier
65 Differential Miter Gear
66 Differential Miter Gear
73 Hex Jam Nut
76 Axle Shaft
80 Torx Head Screws
96 Bearing Sleeve
65
73
Figure 15. Planetary Differential Assembly
11.Install the planetary thrust plate (62).
12.Install the 67T spur gear (60) onto the 21T
sun gear (61).
13.Slide washer (71) onto axle shaft (76).
64
66
67
68
66
63
D
C
B
58
A
REF. Part Name
117 Housing Pin
118 Axle Hub Assembly
119 Hex Nut
ing screws (80), per Table 5, Page 13.
18. After the transaxle has been installed in the
vehicle, install the axle hub assemblies (118),
according to the instructions in “Transaxle installation”, Page 30.
14.Install the two housing pins (117) into the main
housing (1).
15.Apply a bead of sealant to the R.H. housing
(2).
16.Install R.H. housing (2) by sliding it down the
axle shaft (76), over motor shaft assembly
(24, Figure 15) and onto main housing (1).
17.Secure housings by installing the eight hous-
310-3000 IHT 25
Page 30
MOTOR/CENTER SECTION/
for excessive wear (grooving or smearing).
PUMP ASSEMBLY
Refer to Figures 16 and 17, (next pages).
NOTE: Brake Assembly, Input Assembly,
Charge Pump Assembly, and Lower
Housing/Filter/Manifold Assembly have
to be removed before the following steps
can be performed.
DISASSEMBLY
1. Remove washer (82), snap ring (83), washer
(82), 16T pinion gear (28), spacer (27), and
shaft (28).
2. Remove motor thrust bearing retainer (57).
3. Remove motor thrust bearing (25), and 21cc
motor cylinder block assembly (21).
4. Remove each piston (23), spring (18), and
piston seat (22) from the 21cc motor cylinder
block assembly.
5. Remove bypass plate (38) from center section assembly (3).
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)
6. Inspect seal lands of 10cc pump cylinder
block assembly (15) for excessive wear
(grooving or smearing).
ASSEMBLY
1. Install pump cylinder block thrust washer (13)
and spring (14) onto input shaft assembly
(12).
6. Remove the three screws (44) from center
section assembly (3).
7. Lift center section assembly (3) out of main
housing (1).
8. Remove the two center section assembly pins
(43).
9. Remove bypass actuator (39) from the center section (3).
10.Remove 10cc pump cylinder block assembly (15).
11.Remove each piston (17), spring (18), piston seat (16) from the 10cc pump cylinder
block assembly (21).
12.Remove block spring (14), and block thrust
washer (13) from shaft (12, Figure 10)
INSPECTION
2. Install piston washers (18), springs (17), and
pistons (18) in cylinder block (15).
3. Install pump cylinder block assembly (15). Be
sure spring tension is even around the entire
block.
4. Install the two center section assembly pins
(43).
5. Install center section assembly (3) into main
housing (1). Make sure center section seats
fully on its mating surface.
6. Secure center assembly section (3) by installing three screws (44) reference Table 5,
Page 13. Apply a few drops of loctite on
screws when installing.
7. Install bypass plate (38) into center section
assembly (3).
1. Inspect running surface of thrust bearing (25)
310-3000 IHT
26
Page 31
Break sharp edges, both sides
NOTE: To hold bypass plate (38) in position, apply a small drop of grease to its
slot before installing.
8. Install spacer (27), 16T pinion gear (28),
washer (82), snap ring (83), and washer (82)
onto motor shaft (24).
13.Again using the assembly tool to compress
pistons (22), slide thrust bearing (25), behind
the tool, into its cavity in front of the cylinder
block (21) and assembled pistons.
NOTE: The thick race of thrust bearing
(25) must face the pistons.
9. Insert the motor shaft assembly far enough to
seat the motor cylinder block (21).
10.Install piston washers (18), springs (17), and
pistons (16) in cylinder block (21).
11.If not already available, make an assembly
tool from 28 ga. sheet metal as shown in Figure 16. The assembly tool must be free of
burrs and rough edges.
12.Using the assembly tool to compress pistons
(22), install cylinder block assembly (21). Be
careful not to dislodge bypass plate (38) when
installing the cylinder block assembly.
Use 28 gauge
sheet metal
14.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.
15. Install motor thrust bearing retainer (57)
16.Reassemble the planetary differential assembly and install removed components as directed in their respective assembly procedures.
2.250 inch
1.125 Radius
6.000 inch
Figure 16. Motor Cylinder Block Assembly Tool
310-3000 IHT 27
Page 32
REF. Part Name
1 Main Housing
3 Center Section Assembly
13 Block Insert Washer
14 Block Spring
15 10cc Cylinder Block
16 Pistons
17 Springs
18 Piston Washers
19 Block Spring
Figure 17. Motor/Center Section/Pump Assembly
REF. Part Name
20 Bushing
21 21cc Cylinder Block
22 Pistons
23 Springs
24 Motor Shaft
25 Thrust Bearing
27 Spacer
28 16t Pinnion Gear
REF. Part Name
38 Bypass Plate
43 Pin
44 Screws
53 O-Ring
57 Bearing Retainer
82 Washer
83 Retaining Ring
144 O-ring
310-3000 IHT
28
Page 33
DIRECTIONAL CONTROL
91030
11
ASSEMBLY
Refer to Figure 18.
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).
INSPECTION
1. Visually inspect (in place) the two cradle bearings (9), which are staked in upper housing.
Do not remove the Cradle Bearings (9) from
housing (1).
ASSEMBLY
1. Install slot guide (30).
1
REF. Part Name
1 Main Housing
9 Cradle Bearing
10 Variable Swashplate
11 Thrust Bearing
30 Slot Guide
Figure 18. Directional Control Assembly
9
(not removable)
30
11
2. Assemble swashplate assembly (10) by installing thrust bearing (11) into swashplate
(10).
Note: Assemble thrust bearing with thick
race facing pistons.
3. 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.
.
310-3000 IHT 29
Page 34
TRANSAXLE
ASSEMBLY AFTER A
INSTALLATION
Use the following procedure to complete installation 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 13) on
the shaft. Install hex nut (119, Figure 13).
3. With the vehicle raised, install the wheel on
the hub, and retain with the wheel lug nuts.
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.
5. Tighten the wheel lug nuts.
COMPLETE TEAR-DOWN
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.
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 19.
1. Assemble the Directional Control Assembly
(Page 29).
2. Assemble the Motor/Center Section/Pump
Assembly (Page 26,27,28).
3. Assemble the Planetary Differential Assembly (Page 24,25).
4. Assemble the Lower Housing/Filter/Manifold
Assembly (Page 23).
5. Assemble the Charge Pump Assembly
(Page 22).
6. Assemble the Input Shaft Assembly (Page
21).
7. Assemble the Fan and Pulley Assembly
(Page 20).
8. Assemble the Torque Bracket Assembly
(Page 19).
9. Assemble the Control Arm Assembly (Page
17,18).
10.Assemble the Bypass Assembly (Page 16).
11.Assemble the Brake Assembly (Page 14,15).
310-3000 IHT
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Figure 19. 310-3000 IHT Exploded View
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ITEMS LIST
Part numbers are not provided in this manual. See microfiche or parts manual for part numbers.
NO. DESCRIPTION
1 Main Housing Assembly
2 R.H. Housing Assembly
3 Center Section Assembly
4 Spacer
5 Lip Seal
6 Wire Retaining Ring
7 Retaining Ring
8 Ball Bearing
9 Cradle Bearing
10 Variable Swashplate
11 Thrust Bearing
12 Input Shaft
13 Block Thrust Washer
14 Block Spring
15 10cc Cylinder Block Assembly
21 21cc Cylinder Block Assembly
24 Output (Motor) Shaft
25 Thrust Bearing
26 Control Arm
27 Spacer
28 16T Pinion Gear
29 Cap Screw M6 X 1-22
30 Slot Guide
31 Trunnion Arm
32 Trunnion Bushing
33 Lip Seal
34 Return Arm
35 Actuating Arm
36 Stud 5/16 - 24
37 Friction Puck
38 Bypass Plate
39 Bypass Actuator
40 Lip Seal
41 Bypass Arm
42 Retaining Ring
43 Pin
44 Screw
46 Neutral Spring
48 Adjusting Puck
50 Screw , Self-Tapping
51 Lower Cover
52 Gerotor Assembly
53 O-Ring
54 Gerotor Cover
55 Filter
56 Charge Manifold
57 Retainer, Motor Bearing
58 Pin, Carrier
59 15T Planet Gear
60 67T Spur Gear
61 21T Sun Gear
62 Planet Thrust Plate
63 51T Ring Gear
64 Planetary Carrier
65 Miter Gear, Differential (SPLINED)
66 Miter Gear, Differential
67 Shaft , Differential
68 Differential Thrust Plate
69 Flange Bearing
70 Washer
71 Washer
73 Hex Jam Nut, 5/8 - 18
74 Ball Bearing 6205-1
75 Seal, 1” ID X 2.0472” X 0.375”
76 Shaft, Axle
77 Washer
NO. DESCRIPTION
79 Gasket Material/Sealant
80 Torx Head Screw 5/16 - 18
81 Needle Bearing
82 Washer
83 Retaining Ring
84 Lip Seal
85 Brake Disc
87 Washer
88 Screw 5/16 - 24 X 1-3/4
89 Bearing
90 Spacer, Locating
91 O-Ring
92 Countersunk Screw
93 Spring Spacer
94 Spacer
95 Nut, Hex Lock 5/16 - 24
96 Sleeve Bearing
97 20W50 Oil
102 Torque Bracket
103 Pulley
104 Fan
106 Spacer, Trunnion
107 Screw
109 Vent Bushing
110 Fitting Kit
111 Cap-Vent Assembly
113 Hose/ Fitting Assembly
115 Jam Nut
116 Retaining Ring
117 Std Hlds Pins
118 Hub Assembly 7/16 - 14
119 Nut, Hex 3/4 - 16
120 Puck, Brake
121 Rib Neck Bolt, 2”
122 Brake Yoke
123 Bolt, Square-Head
124 Arm, Brake
125 Pins, Brake
126 Lock Washer, 1/4"
127 Nut, 1/4 - 20
128 Nut, Castle
129 Cotter Pin
130 Spacer
131 Puck Plate
132 Rib Neck Bolt, 3”
133 Wheel Stud 7/16-14
134 Brake Spring
136 Extension Spring
137 Spring Pin
138 Screw , Stap 10-32 X .5
139 Washer
141 Spring, Brake Arm Bias
142 Hex Lock Nut 5/16 - 18
143 Bolt 5/16 -15 X 2.5
144 O-Ring
145 Spring, Relief
146 Ball , 7/16
151 Compression Spring Brake Anti-Drag
152 Brake Pull Rod
153 Plug, Straight Thread
154 Wire Retaining Ring
155 Fan/ Pulley Assembly
157 Screw O-Ring
180 Manifold Kit
202 Manifold O-Ring Kit
203 Seal Kit (310-3000)
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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).
Bantam Duty: A descriptive term relating to the product capacity (meaning: light duty).
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 gas-
eous 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”
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Hydrostatic Transaxle: A multicomponent assembly including a gear case and a hydrostatic trans-
mission.
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 spe-
cific operating pressure.
Scoring: Scratches in the direction of motion of mechanical parts caused by abrasive contami-
nants.
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.
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