Hydro-Gear 310 3000 Hydrostatic Transaxle Service and Repair Manual

Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
310-3000
Integrated Hydrostatic Transaxle
Service and Repair Manual
BLN-51259
Revision Dec. 2008
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Table of Contents
Section
Page
Foreword........................................................................................................................ i
Description and Operation........................................................................................... ii
Introduction.................................................................................................................. 1
General Description....................................................................................................................
Introduction.................................................................................................................................
Hydraulic Schematic....................................................................................................................
Technical Specifications............................................................................................................
Product Identification..................................................................................................................
1
1
2
3
3
Safety............................................................................................................................. 4
Personal Safety...........................................................................................................................
Tool Safety...................................................................................................................................
Work Area Safety.........................................................................................................................
Servicing Safety...........................................................................................................................
4
4
4
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
310-3000 IHT
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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 the 3103000 Hydro-Gear 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 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
310-3000 IHT
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 ESA (Engine Service Association)
(610) 363-3844 or their Hydro-Gear 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, visit www.hydro-gear.com or call our
Technical Service Department at (217) 728-2581.
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SECTION 1. DESCRIPTION AND OPERATION
INTRODUCTION
The purpose of this manual is to provide useful information for servicing the Hydro-Gear®
310-3000 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 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.
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-
ii
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 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 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 310-3000 utilizes an in-line floating disc
brake controlled by a "cam" style actuating
arm.
310-3000 IHT
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310-3000 IHT
Figure 1. 310-3000 Hydraulic Flow Illustration
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.
310-3000 IHT
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
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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 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.
Table 1. 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
TECHNICAL
SPECIFICATIONS
Technical specifications for the 310-3000 IHT
are given in Table 1.
Brake Type
PRODUCT IDENTIFICATION
Weight of Unit
Disc
58 lb; 26 kg
The model and configuration of the 310-3000
IHT can be determined from the label shown
in Figure 2.
HYDRO - GEAR
S U L L I VA N , I L . U . S . A .
OEM Model
Number
165758
8 328 T1 476
310-3000
Hydro-Gear
Number
Made in U.S.A.
Serial Number
(unique for that model - for that day)
Year Built
Date
(Julian - day of year)
Type of Product and Build Information
Figure 2. 310-3000 Configuration Label
2
310-3000 IHT
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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 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.
310-3000 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 310-3000IHT
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
Possible Cause
Corrective Action
Refer To:
UNIT OPERATES IN ONE DIRECTION ONLY
Control linkage bent or out of adjustment Repair or replace linkage
Control Linkage Repair, Page 17
Repair or replace drive belt or pul- Pulley Repair, Page 20
Drive belt slipping or pulley damaged
ley
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 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
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 17
Brake Adjustment, Page 8
Pulley Repair, Page 20
Fluid Maintenance, Page 7
Vehicle Specifications
Bypass Repair, Page 16
Purging Procedure, Page 11
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 8
Cooling Fan Repair, Page 20
Fluid Maintenance, Page 7
Vehicle Specifications Purging
Procedure, Page 11
TRANSAXLE LEAKS OIL
Damaged seals, housing, or gaskets
Air trapped in hydraulic system
4
Replace damaged component
Purge hydraulic system
Appropriate Repair Procedure
Purging Procedure, Page 11
310-3000 IHT
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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 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
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.
4. Inspect the transaxle cooling fan for broken
or distorted blades and remove any obstructions (grass clippings, leaves dirt, etc.).
310-3000 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 11.
Using the transaxle removal procedure from
Section 5, Page 12, 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 11.
In the event a 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
Volume
20W-50 engine oil
0.95 gal. (121.6 oz) (3.59 liters)
FLUID FILL PORT
Figure 3. 310-3000 Fluid Fill and Level Ports
6
310-3000 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.
310-3000 IHT
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
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.
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RETURN TO NEUTRAL SETTING
HAND 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
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.
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.
4. Apply the vehicle brake, start the engine and
increase the throttle to full engine rpm.
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.
BRAKE PULL ROD
CONTROL ARM
RETURN ACTUATING ARM
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!
8
ADJUSTING PUCK
COTTER PIN AND WASHER
(HIDDEN)
Figure 4. Return to Neutral, Hand Control
310-3000 IHT
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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 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.
CONTROL ARM
RETURN
ACTUATING
ARM
2. Remove the Original Equipment Manufacturer’s (OEM’s) control linkage at the control
arm. Refer to Figure 5.
ADJUSTING
PUCK
WARNING
Do not attempt any adjustments with the
engine running. Use extreme caution
while inspecting all vehicle linkage!
Figure 5. Return to Neutral, Foot Control
Follow all safety procedures outlined in
the vehicle owner’s manual!
310-3000 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.
10
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 op er at ing tem per a tures. 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
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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 3103000 IHT is provided in Table 4, Page 13.
TORQUE SPECIFICATIONS
Torque specifications for fasteners used on the
310-3000 IHT are provided in Table 5.
310-3000 IHT
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.
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11
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
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.
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.
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
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
Center Section Screws (Item #4)
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)
Fan Screws (Item # 107)
Bypass Screw (Item # 138)
Torque Bracket Nut (Item # 142)
Control Arm Stud (Item # 36)
Trunnion Shaft Nut (Item # 95)
Control Bearing Screw(Item # 92)
Control Arm Nut (Item # 95)
Adjusting Puck Screw (Item # 88)
Brake Nuts (Item # 127)
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)
35-50 lb-in (4-6 Nm)
42-62 lb-in (5-7 Nm)
160-210 lb-in (18-24 Nm)
50-120 lb-in (6-14 Nm)
180-240 lb-in (20-27 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)
44
50
29
73
80
119
115
107
138
142
36
95
92
95
88
127
12
Description
Screw
Screw
M6 x 1-22
5/16-18
5/16-18
3/4-16
Jam Nut
Screw
10-32 x 1/2
5/16-18
5/16-24
5/16-24
Screw
5/16-24
5/16-24 x 1-3/4
1/4-20
310-3000 IHT
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BRAKE ASSEMBLY
(128), and washer (77).
5. Remove brake arm (124), and brake arm
bias spring (141).
Refer to Figures 6 and 7.
DISASSEMBLY
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).
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).
2. Remove cotter pin (129), and washer (77)
from brake pull rod (152).
8. Remove lower nut (127), and lock washer
(126) se cur ing brake yoke assembly
(122).
3. Remove brake pull rod (152) and set
aside.
9. Remove brake yoke assembly (122), puck
plate (131), and outer brake puck (120).
4. Remove the cotter pin (129), castle nut
10. Remove brake disc (85), and inner brake
puck (120).
REF.
2
77
85
95
120
122
123
124
125
126
Part Name
Right Hand Housing Assembly
Washer
Brake Disk
Lock Nut
Brake Puck
Brake Yoke Assembly
Square Head Bolt
Brake Arm
Brake Pin
Lock Washer
REF.
127
128
129
130
131
134
139
141
151
152
Part Name
Nut
Castle Nut
Cotter Pin
Spacer
Puck Plate
Brake Spring
Washer
Brake Arm Bias Spring
Anti-Drag Compression Spring
Brake Pull Rod
Figure 6. Brake Assembly
310-3000 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
INSPECTION
1. Inspect the brake pucks (120) for excessive
wear.
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”) (.381 mm)
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.
6. Install brake anti-drag compression spring
(151), and two brake pins (125).
7. Install brake arm (124) onto brake yoke assembly.
8. Install washer (77), and castle nut (128).
9. Insert a (0.015”) (.381 mm) 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”) (.381 mm) 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.
5.64 + 0.06
BRAKE ROD ASSEMBLY
Figure 7. Brake Pull Rod Assembly Adjustment
14
310-3000 IHT
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BYPASS ASSEMBLY
Refer to Figure 8.
DISASSEMBLY
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).
REF.
1
40
41
42
136
137
138
Part Name
Main Housing
Lip Seal
Bypass Arm
Retaining Ring
Spring
Spring Pin
Screw
Figure 8. Bypass Assembly
310-3000 IHT
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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.
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. (14 Nm),
then back off (1) full turn.
NEUTRAL ASSEMBLY
1. Install washer (87), return arm (34), actuating arm (35), and neutral spring (46).
2. Install adjusting puck (48), and bolt (88).
INSPECTION
1. Inspect bearing (89), and replace if neces sary. Remove bear ing by removing
countersink screw (92), and washer (90).
16
2. Inspect trunnion arm lip seal (33), and replace if necessary.
3. Reference Pages 9, 10 for proper neutral
adjustment procedures.
310-3000 IHT
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REF.
26
31
32
33
34
35
36
37
46
48
Part Name
Control Arm
Trunnion Arm
Trunnion Bushing
Trunnion Arm Lip Seal
Return Arm
Actuating Arm
Stud
Friction Puck
Spring
Adjusting Puck
REF.
77
87
88
89
90
92
93
94
95
106
Part Name
Washer
Washer
Screw
Bearing
Locating Spacer
Countersink Screw
Spring
Spacer
Locknut
Trunnion Spacer
Figure 9 Control Arm Assembly
310-3000 IHT
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17
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
TORQUE BRACKET
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
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.
18
REF.
1
102
142
143
Part Name
Main Housing
Torque Bracket
Lock Nut
Bolt
Figure 10. Torque Bracket Assembly
310-3000 IHT
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FAN AND PULLEY
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.
REF.
1
12
103
104
107
115
Part Name
Main Housing
Input Shaft
Pulley
Fan
Screw
Jam Nut
Figure 11. Fan and Pulley Assembly
310-3000 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
INPUT SHAFT ASSEMBLY
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).
3. Remove input shaft assembly (12), (8),
(6).
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
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.
Figure 12. Input Shaft Assembly
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).
4. Secure input shaft assembly (12) by installing retaining ring (7).
20
310-3000 IHT
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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. 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.
REF.
1
29
52
53
54
Part Name
Main Housing
Screw
Gerotor Assembly
O-ring
Gerotor Cover
Figure 13. Charge Pump Assembly
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.
4. Secure charge pump cover (54) by installing
two screws (29), per Table 5, Page 13.
310-3000 IHT
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LOWER HOUSING/FILTER/
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. 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).
REF.
1
29
49
50
51
52
53
54
Part Name
Main Housing
Capscrew
Not Used
Screws
Lower Cover
Gerotor Assembly
O-Ring
Gerotor Cover
REF.
55
56
144
145
146
156
157
Part Name
Filter
Charge Manifold
O-Ring
Spring
Ball
Manifold O-Ring
Screw O-Ring
Figure 14. Lower Housing/Filter/Manifold Assembly
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.
22
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PLANETARY DIFFERENTIAL
ASSEMBLY
2. Remove all sealant from both housings and
inspect seal lands for damage when cleaning.
Refer to Figure 15, next page.
3. If miter gear (65) needs replaced, remove jam
nut (73) from axle shaft (76).
NOTE: Brake Assembly, and optional Return to Neutral have to be removed before
the following steps can be performed.
ASSEMBLY
1. Remove the axle hub assembly (118) on control
side by removing nuts (119), and hub assemblies (118).
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. Remove the eight torx head screws (80) that
secure the R.H. housing assembly (2).
2. Install differential thrust plate (68) into main
housing (1).
3. Remove R.H. housing assembly (2), while
holding axle shaft (76) in place.
3. Install planetary carrier (64) into main housing
(1).
4. Remove the two housing pins (117).
5. Remove washer (71) from axle shaft (76).
4. Reassemble the two miter gears (66) onto differential shaft (67), and install assembly into
planetary carrier (64).
6. Remove spur gear (60), and thrust plate
(62).
5. Install 51T ring gear (63) into main housing
(1).
7. Remove 21T sun gear (61), and sleeve bearing
(96).
6. Install the four carrier pins (58) into planetary
carrier (64).
8. Remove the planetary gears (59).
9. Remove washer (70), and axle shaft (76).
7. If necessary, reassemble axle shaft assembly
(76) by installing washer (70), miter gear (65),
and jam nut (73) onto axle shaft (76).
10. Remove the four carrier pins (58) from planetary carrier (64).
8. Install R.H. Axle shaft assembly (76) partway
into assembled differential components.
11. Remove 51T ring gear (63) from main housing
(1).
NOTE: It will be necessary to support the RH
axle shaft in the partially installed position
while steps 9 through 16 are completed.
DISASSEMBLY
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.
310-3000 IHT
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 R.H. axle shaft
with the bevel gears in the differential assembly. Continue to support the R.H. axle shaft.
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23
Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
D
B
C
A
REF.
1
2
58
59
60
61
62
63
64
65
66
67
68
Part Name
Main Housing
R.H. Housing Assembly
Carrier Pin
REF. Part Name
Planetary Gears
70 Washer
67t Spur Gear
71 Washer
21t Sun Gear
63 51t Ring Gear
Planetary Thrust Plate
64 Planetary Carrier
51t Ring Gear
65 Differential Miter Gear
Planetary Carrier
66 Differential Miter Gear
Differential Miter Gear
73 Hex Jam Nut
Differential Miter Gear
76 Axle Shaft
Differential Shaft
80 Torx Head Screws
Differential Thrust Plate
96 Bearing Sleeve
C
A
REF.
117
118
119
D
B
Part Name
Housing Pin
Axle Hub Assembly
Hex Nut
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).
14. Install the two housing pins (117) into the
main housing.
15. Apply a bead of sealant to the R.H. housing (2).
24
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
housing 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.
310-3000 IHT
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MOTOR/CENTER SECTION/
PUMP ASSEMBLY
Refer to Figures 16 and 17, (next pages).
NOTE: Brake Assembly, Input Assembly,
Charge Pump Assembly, and Low er
Housing/Filter/Manifold Assembly have
to be removed before the following steps
can be performed.
(25) for excessive wear (grooving or smearing).
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).
1. Remove washer (82), snap ring (83), washer
(82), 16T pinion gear (28), spacer (27), and
shaft (28).
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.
2. Remove motor thrust bearing re tain er
(57).
5. Inspect each piston (17), spring (18), piston
seat (16).
3. Remove motor thrust bearing (25), and 21cc
motor cylinder block assembly (21).
6. Inspect seal lands of 10cc pump cylinder
block assembly (15) for excessive wear
(grooving or smearing).
DISASSEMBLY
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).
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
ASSEMBLY
1. Install pump cylinder block thrust washer
(13) and spring (14) onto input shaft assembly (12).
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
310-3000 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
NOTE: To hold bypass plate (38) in position, apply a small drop of grease to its
slot before installing.
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.
8. Install spacer (27), 16T pinion gear (28),
washer (82), snap ring (83), and washer
(82) onto motor shaft (24).
NOTE: The thick race of thrust bearing
(25) must face the pistons.
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.
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).
15. Install motor thrust bearing retainer (57)
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.
16. Reassemble the planetary differential assembly and install removed components
as directed in their respective assembly
procedures.
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.
Break sharp edges, both sides
Use 28 gauge
sheet metal
2.250 inch
1.125 Radius
6.000 inch
Figure 16. Motor Cylinder Block Assembly Tool
26
310-3000 IHT
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REF.
1
3
13
14
15
16
17
18
19
Part Name
Main Housing
Center Section Assembly
Block Insert Washer
Block Spring
10cc Cylinder Block
Pistons
Springs
Piston Washers
Block Spring
REF.
20
21
22
23
24
25
27
28
Part Name
Bushing
21cc Cylinder Block
Pistons
Springs
Motor Shaft
Thrust Bearing
Spacer
16t Pinnion Gear
REF. Part Name
38
43
44
53
57
82
83
144
Bypass Plate
Pin
Screws
O-Ring
Bearing Retainer
Washer
Retaining Ring
O-ring
Figure 17. Motor/Center Section/Pump Assembly
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
DIRECTIONAL CONTROL
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.
REF.
1
9
10
11
30
Part Name
Main Housing
Cradle Bearing
Variable Swashplate
Thrust Bearing
Slot Guide
2. Remove slot guide (30).
Figure 18. Directional Control Assembly
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).
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.
28
310-3000 IHT
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TRANSAXLE 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).
ASSEMBLY AFTER A
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.
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 19.
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 29).
5. Tighten the wheel lug nuts.
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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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
Figure 19. 310-3000 IHT Exploded View
30
310-3000 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
ITEMS LIST
Part numbers are not provided in this manual. See Service Schematic or Distributor for part numbers.
NO.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
21
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
46
48
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
73
74
75
76
77
DESCRIPTION
Main Housing Assembly
R.H. Housing Assembly
Center Section Assembly
Spacer
Lip Seal
Wire Retaining Ring
Retaining Ring
Ball Bearing
Cradle 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
16T Pinion Gear
Cap Screw M6 X 1-22
Slot Guide
Trunnion Arm
Trunnion Bushing
Lip Seal
Return Arm
Actuating Arm
Stud 5/16 - 24
Friction Puck
Bypass Plate
Bypass Actuator
Lip Seal
Bypass Arm
Retaining Ring
Pin
Screw
Neutral Spring
Adjusting Puck
Screw , Self-Tapping
Lower Cover
Gerotor Assembly
O-Ring
Gerotor Cover
Filter
Charge Manifold
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
Washer
Hex Jam Nut, 5/8 - 18
Ball Bearing 6205-1
Seal, 1” ID X 2.0472” X 0.375”
Shaft, Axle
Washer
310-3000 IHT
NO.
79
80
81
82
83
84
85
87
88
89
90
91
92
93
94
95
96
97
102
103
104
106
107
109
110
111
113
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
136
137
138
139
141
142
143
144
145
146
151
152
153
154
155
157
180
202
203
DESCRIPTION
Gasket Material/Sealant
Torx Head Screw 5/16 - 18
Needle Bearing
Washer
Retaining Ring
Lip Seal
Brake Disc
Washer
Screw 5/16 - 24 X 1-3/4
Bearing
Spacer, Locating
O-Ring
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
Rib Neck Bolt, 2”
Brake Yoke
Bolt, Square-Head
Arm, Brake
Pins, Brake
Lock Washer, 1/4"
Nut, 1/4 - 20
Nut, Castle
Cotter Pin
Spacer
Puck Plate
Rib Neck Bolt, 3”
Wheel Stud 7/16-14
Brake Spring
Extension Spring
Spring Pin
Screw , Stap 10-32 X .5
Washer
Spring, Brake Arm Bias
Hex Lock Nut 5/16 - 18
Bolt 5/16 -15 X 2.5
O-Ring
Spring, Relief
Ball , 7/16
Compression Spring Brake Anti-Drag
Brake Pull Rod
Plug, Straight Thread
Wire Retaining Ring
Fan/ Pulley Assembly
Screw O-Ring
Manifold Kit
Manifold O-Ring Kit
Seal Kit (310-3000)
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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).
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
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”
32
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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.
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
NOTES
34
310-3000 IHT
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NOTES
310-3000 IHT
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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983
© 2008 HYDRO-GEAR
Rev. P2
Printed in U.S.A.
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