Hydro-Gear EZT 310-2200 Integrated Zero-Turn Transaxle Service and Repair Manual

Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

310-2200 EZT

®

Integrated Zero-Turn Transaxle

Service and Repair Manual

BLN-51856

December 2008

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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

TABLE OF CONTENTS

Section Page

Foreword ............................................................................................................................. 1

Description and Operation ................................................................................................ 2

Introduction .................................................................................................................................................. 2

General Description ..................................................................................................................................... 2

Hydraulic Schematic .................................................................................................................................... 3

External Features 310-2200 ......................................................................................................................... 4

Technical Specifications ............................................................................................................................... 5

Product Identification ................................................................................................................................... 5

Safety .................................................................................................................................. 6

Personal Safety ........................................................................................................................................... 6

Tool Safety ................................................................................................................................................... 6

Work Area Safety ........................................................................................................................................ 6

Servicing Safety ........................................................................................................................................... 6

Troubleshooting ................................................................................................................. 7

Service and Maintenance .................................................................................................. 8

External Maintenance .................................................................................................................................. 8

Service and Maintenance Procedures .......................................................................................................... 8

Fluids .......................................................................................................................................................... 8

Fluid Volume and Level ................................................................................................................................ 8

Fluid Change Procedure .............................................................................................................................. 9

Purging Procedures ................................................................................................................................... 10

Return to Neutral Setting ........................................................................................................................... 11

Repair ................................................................................................................................ 13

How To Use This Section ........................................................................................................................... 13

General Instructions ................................................................................................................................... 13

Transaxle Removal..................................................................................................................................... 13

Limited Disassembly ................................................................................................................................. 13

Tools and Torques ...................................................................................................................................... 14

Control Arm and Bypass Arm ..................................................................................................................... 15

Seal Kit Replacement ................................................................................................................................ 16

Cog Brake and Side Housing ..................................................................................................................... 17

Axle Shaft, Reduction Gears and Expansion Plate .................................................................................... 18

Motor Shaft ................................................................................................................................................ 19

Input Shaft and Bypass Rod ...................................................................................................................... 20

Hydraulic Components .......................................................................................................................... 21-25

Transaxle Installation ................................................................................................................................. 25

Assembly After a Complete Teardown ........................................................................................................ 26

Sealant Application........................................................................................................... 27

Parts List ..................................................................................................................... 28, 29

Glossary of Terms ...................................................................................................... 30, 31

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FOREWORD

Headquartered in Sullivan, Illinois, Hydro-Gear

® is a world leader in the design, manufacture, and service of quality hydrostatic transaxles for the lawn and garden industry. The mission of our company is to be recognized by our customers and the industry as a world-class supplier and the quality leader in everything we do.

This Service and Repair Manual is designed to provide information useful in servicing and troubleshooting the Hydro-Gear 310-2200 EZT

®

Integrated Zero-Turn Transaxle.

Also included is a glossary of terms that are frequently used throughout the industry and in

Hydro-Gear service publications. Understanding terminology is very important!

It is necessary, and a good shop practice, that your service area be equipped with the proper tools and the mechanics be supplied the latest information available. All repair procedures illustrated in this guide are suggested, but preferred methods of repair.

Repair procedures require that the transaxle unit be removed from the vehicle.

This is not a certification, test or study guide for a certification test. If a technician is interested in certification, they should contact an agent representing the ESA (Engine Service Association) at (610) 363-3844 or their Hydro-Gear

Central Service Distributor. Many distributors will be hosting certification testing. These study guides will cover most of the products and manufacturers in our industry.

For more information about Hydro-Gear or our products, please contact your Central Service

Distributor, or call our Customer Service Department at (217) 728-2581.

310-2200 EZT ®

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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

SECTION 1. DESCRIPTION AND OPERATION

INTRODUCTION

The purpose of this manual is to provide information useful in servicing the Hydro-Gear

®

Integrated Zero-Turn Transaxle (EZT

®

). This manual includes the EZT’s general descriptions, hydraulic schematics, technical specifications, servicing and troubleshooting 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 exterior of the transaxle will need to be thoroughly cleaned before beginning most procedures. Do not wash the transaxle while it is hot.

Do not use a pressure washer to clean the unit.

GENERAL DESCRIPTION

The 310-2200 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 10cc per revolution, and motor with a fixed displacement of 10cc per revolution. The variable displacement pump features a trunnion mounted swashplate with a direct-proportional displacement control. Reversing the direction of the swashplate 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 310-2200 has a self contained fluid supply and an internal filter. The fluid is forced through the filter by a positive “head” on the fluid in the housing/expansion tank with an assist by the negative pressure created in the pump pistons as they operate.

The check valves in the center section are used to control the make-up flow of the fluid to the low pressure side of the loop.

A cam style, block lifting bypass is utilized in the

310-2200 to permit moving the vehicle for a short distance at a maximum of 2 m.p.h. (3.2 Km/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.

2

Figure 1. Hydraulic Schematic

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310-2200 EZT

®

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310-2200 EZT

®

HYDRAULIC FLOW SCHEMATIC

HYDRAULIC SCHEMATIC

Figure 2 provides an illustration of the hydraulic oil circuit. The oil supply for the hydraulic system of the 310-2200 EZT ® is also utilized for lubricating the components of the final drive assembly.

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 variable 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 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 pump swashplate is increased the amount of oil being pumped will

Figure 2. Hydraulic Flow Illustration

increase and cause a higher speed 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 transaxle housing, then is pulled back into one of the check valves depending upon the direction of vehicle operation. All of this oil must pass through an internal filter.

The motor cylinder block mounts onto a splined motor shaft which drives the gear train.

The bypass feature in the 310-2200 has a mechanical lever which lifts the motor block off of the center section running surface. This allows oil flow from the cylinder blocks to be discharged.

310-2200 EZT ® 3

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EXTERNAL FEATURES 310-2200

4

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310-2200 EZT

®

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TECHNICAL SPECIFICATIONS

Technical specifications for the 310-2200 EZT

®

are listed in Table 1.

Input Speeds

Maximum: 3000 RPM

Minimum: 1800 RPM

Table 1. Technical Specifications

Maximum Tire Diameter

20 inch; 508 mm

Weight of Unit

29.0 lbs. (13.15 Kg)

Maximum Weight on Drive Tires

300 lbs. (136 Kg) with 20” Tires

340 lbs. (154 Kg) with 18” Tires

Table 2. 310-2200 EZT

®

Component Options

C o m p o n e n t

A x l e S h a f t D i a m e t e r a

B

B r a r a k e k e

L o c a t i o n :

T y p e :

C o n t r o l A r m L o c a t i o n : n d E n d

C o n t r o l

O v e r a ll

A r r a n g e m e

T r a n s a x l e R n t s : e d u c t i o n :

O p t i o n s :

C o m p o n e n t O p t i o n s

3 / 4 " D D

I n b o a r d

C o g

I n b o a r d

S t a n d a r d

1 9 .

2 : 1

C o n t r o l A r m

1 " F l a n g e

O u t b o a r d

F ir c it o n D

O u t b o a r d i s c

R T N (

2 1 .

2 : 1 s c i s s o r s t y l e )

1 " D D v a ir o u s l e n g t h s

PRODUCT IDENTIFICATION

The model and configuration of the 310-2200 EZT ® can be determined from the label shown in Figure 3.

310-2200 EZT ®

Figure 3. Configuration Label

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6

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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

310-2200 EZT

®

, fully read and understand the safety precautions described in this section.

PERSONAL SAFETY

Certain safety precautions must be observed while servicing or repairing the 310-2200 EZT

®

.

This section addresses some of these precautions but must not be considered an all-inclusive source on safety information. This section is to be used in conjunction with all other safety material which may apply, such as:

1) Other manuals pertaining to this machine,

2) Local and shop safety rules and codes,

3) Governmental safety laws and regulations.

Be sure that you know and understand the equipment and the hazards associated with it. Do not place speed above safety.

Notify your supervisor whenever you feel there is any hazard involving the equipment or the performance of your job.

Never allow untrained or unauthorized personnel to service or repair the equipment.

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.

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.

310-2200 EZT

®

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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.

In many cases, problems with the 310-2200 are not related to a defective transaxle, 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,

Service and Maintenance, before assuming the pump is malfunctioning. Table 3 below provides a troubleshooting checklist to help determine the cause of operational problems.

Table 3. 310-2200 EZT ® Troubleshooting Checklist

Possible Cause Corrective Action

UNIT OPERATES IN ONE DIRECTION ONLY

Control linkage bent or out of adjustment

Drive belt slipping or pulley damaged

Repair or replace linkage, Page 8

Repair or replace drive belt or pulley, Page 8

VEHICLE DOES NOT DRIVE/TRACK STRAIGHT

Vehicle tires improperly inflated

Control linkage bent or out of adjustment

Bypass assembly sticking

Refer to vehicle manufacturer suggested pressure

Repair or replace linkage, Pages 8 and 11

Repair or replace bypass, Page 20

Oil level low or contaminated oil

Excessive loading

Loose parts

Bypass assembly sticking

Air trapped in hydraulic system

UNIT IS NOISY

Fill to proper level or change oil, Page 9

Reduce vehicle loading, Page 8

Repair or replace loose parts

Repair or replace linkage

Purge hydraulic system, Page 10

Engine speed low

Control linkage bent or out of adjustment

Drive belt slipping or pulley damaged

Oil level low or contaminated oil

Excessive loading

Bypass assembly sticking

Air trapped in hydraulic system

UNIT HAS NO/LOW POWER

Adjust to correct setting

Repair or replace linkage, Page 8

Repair or replace drive belt or pulley, Page 8

Fill to proper level or change oil, Page 9

Reduce vehicle loading, Page 8

Repair or replace linkage

Purge hydraulic system, Page 10

Debris buildup around transaxle

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

UNIT IS OPERATING HOT

Clean off debris, Page 8

Repair or replace cooling fan

Fill to proper level or change oil, Page 9

Reduce vehicle loading, Page 8

Purge hydraulic system, Page 10

TRANSAXLE LEAKS OIL

Replace damaged component

Purge hydraulic system, Page 10

310-2200 EZT ® 7

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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

Regular external maintenance of the 310-2200

EZT ® should include the following:

1. Check the vehicle operator’s manual for the recommended load ratings. Insure that the current application does not exceed load rating.

2. Check oil level in accordance with Figure 4

Page 9.

3. Inspect the vehicle drive belt, idler pulley(s), and idler spring(s). Insure that no belt slippage can occur. Slippage can cause low input speed to the transmission.

4. Inspect the vehicle control linkage to the directional control arm on the transaxle. Also insure that the control arm is securely fastened to the trunnion arm of the transaxle.

5. Inspect the bypass mechanism on the transaxle and the vehicle linkage to insure that both actuate and release fully.

SERVICE AND MAINTENANCE

PROCEDURES

Some of the service procedures presented on the following pages can be performed while the

310-2200 is mounted on the vehicle. Any repair procedures as mentioned in the repair section of this manual must be performed after the unit has been removed from the vehicle.

FLUIDS

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

9.0 cSt (55 SUS) at 230° F (110° C) and an API classification of SL is recommended. A 20W50 engine oil has been selected for use by the factory and is recommended for normal operating procedures.

FLUID VOLUME AND LEVEL

Fluid volume information is provided in Table 4.

Certain situations may require additional fluid to be added or even replaced. Refer to Page 4 and Figure 4 for the proper fill port location.

Fill the 310-2200 so the oil level is .75”-1.50”

(19-38 mm) below the oil fill port.

Recheck the fluid level once the unit has been operated for approximately 1 minute.

Purging will be required. Refer to the purging procedures on Page 10.

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FLUID CHANGE

FLUID CHANGE PROCEDURE

This transaxle is factory filled, sealed and does not require oil maintenance. However, in the event of oil contamination or degradation, oil addition or change may alleviate certain performance problems.

1. Remove the transaxle from the vehicle.

2. Clean the oil fill port area of any debris.

3. Remove the oil fill port fitting.

4. Position the transaxle so the oil will drain completely out of the housing.

5. Fill the transaxle at the oil fill port according to Figure 4.

6. Install the oil fill port fitting.

7. Purging will be required. Refer to the purging procedures on Page 10.

8. Recheck the fluid level once the unit has been operated for approximately 1 minute.

Table 4. Fluid Volumes for the 310-2200 EZT ®

Fluid Description Volume

20W50 engine oil 54.1 fl.oz. (1600 ml) to 57.5 fl.oz. (1700 ml)

Figure 4. Fluid Level and Fill Port

310-2200 EZT ®

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PURGING PROCEDURES

Due to the effects air has on efficiency in hydrostatic drive applications, it is critical that it is purged from the system.

These purge procedures should be implemented any time a hydrostatic system has been opened to facilitate maintenance or any additional oil has been added to the system.

Air creates inefficiency because its compression and expansion rate is higher than that of the oil approved for use in hydrostatic drive systems.

The resulting symptoms in hydrostatic systems may be:

1. Noisy operation.

2. Lack of power or drive after short term operation.

3. High operation temperature and excessive expansion of oil.

Before starting, make sure the transaxle/transmission is at the proper oil level. If it is not, fill to the specifications outlined on Page 9, Figure 4.

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 or

6 times), as air is purged from the unit, the oil level will drop.

2. With the bypass valve closed and the engine running, slowly move the directional control in both forward and reverse directions (5 to

6 times). Check the oil level, and add oil as required after stopping the engine.

3. It may be necessary to repeat Steps 1 and

2 until all the air is completely purged from the system. When the transaxle moves forward and reverse at normal speed purging is complete.

10

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RETURN TO NEUTRAL SETTING

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

310-2200 EZT

®

, fully read and understand the safety precautions described in this section.

The return to neutral mechanism on the transmission is designed to set the directional control into a neutral position when the operator releases the vehicle hand 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 return arm.

2. Remove the Original Equipment Manufacturer’s

(OEM’s) control linkage at the control arm. Refer to Figure 5.

3. Start the engine and increase the throttle to full engine speed.

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.

4. Check for axle rotation. If the axle does not rotate, go to Step 5. If the axle rotates, go to

Step 6.

5. Stop the vehicle’s engine. Reattach and adjust the OEM linkage according to Step 3 and

Step 4. Stop the vehicle engine. Refer to Figure

5.

6. Note the axle directional movement. Stop the vehicle engine. Loosen the RTN adjustment screw until the control arm can be rotated. Rotate the control arm in the opposite direction of the wheel rotation in 5 degree increments.

Tighten the RTN adjustment screw. Refer to table 6. Required Torque values, page 14. Recheck according to steps 3 and 4. Stop the vehicle engine. Reattach and adjust the OEM linkage according to the OEM manual. Recheck according to steps 3 and 4. Refer to Figure 5.

RTN Adjustment Screw

Speed and Directional Control

310-2200 EZT ®

Figure 5. Return to Neutral Setting (Model 618-04163)

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NOTES

12

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®

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SECTION 5. REPAIR

HOW TO USE THIS MANUAL

Each subassembly illustrated in this section is illustrated with an exploded view showing the parts involved. The item reference numbers

in each illustration are for assembly instruc-

tions only. See page 29 for part names and de-

scriptions. A complete exploded view and item list of the transaxle is provided at the end of the repair section.

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 and 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.) material.

Parts requiring replacement must be replaced from the appropriate kits identified in the Items

Listing, found at the end of this manual. Use only original Hydro-Gear

®

replacement parts found in BLN-51427 (CD).

IMPORTANT: When internal repair is performed

on the 310-2200 EZT

®

, the filter assembly must be replaced.

TRANSAXLE REMOVAL

It is necessary to remove the 310-2200 from the vehicle before performing the repair procedures presented in this section.

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.

Reassembly 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 24.

310-2200 EZT ®

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TOOLS AND TORQUES

Table 5. Required Tools

Miscellaneous

310-2200 Service & Repair Manual

Flat Blade Screw Driver (2)

Torque Wrench

Air Impact Wrench

Rubber Mallet

Breaker Bar

Side Cutters/Snips

Pliers

Needle Nose

Large External Snap Ring

Small Internal Snap Ring

Sockets

1/2”-3/8” Adapter

3/8” Deep

1/2” Deep

7/16” Deep

9/16” Deep

3/4” Deep

13/16” Deep

7/8”

T-25 Torx Head

T-40 Torx Head

Apex AN-08

Operation

Side Housing Screws

Control Arm Screw

Control Arm Stop Stud

Center Section Bolts

Check Plugs

Expansion Plate Screws

Fan/Pulley Lock Nut

Cog Brake Bolt

RTN Adjustment Screw

Hub Nut

Table 6. Required Torque Values

Torque

135-185 lb-in [15-21 Nm]

230-310 lb-in [26-35 Nm]

50-120 lb-in [6-18 Nm]

525-700 lb-in [60-80 Nm]

200-360 lb-in [23-41 Nm]

25-50 lb-in [3-6 Nm]

360-520 lb-in [41-59 Nm]

80-120 lb-in [9-14 Nm]

85-120 lb-in [10-14 Nm]

100-160 lb-ft [136-217 Nm]

Item

9

25

21

12

56

53

122

55

131

99

Description

Screw 1/4-20 x 1.25

Screw 5/16-24 x 1

Stud 5/16-24

Screw 3/8-24 x 2.5

Check Plug Assembly

Screw 10-32 x 0.50

Lock Nut 1/2 x 20

Bolt 1/4-20 x 1

Screw 5/16-24 x 1.00

Nut, Hex 3/4-16 Lock

14

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Refer to Figure 6.

Disassembly

1. Loosen and remove the lock nut (26) and flat washer (24). Discard the lock nut (26) and flat washer (24).

2. Remove the torx head screw (25) from the directional control.

3. Remove control arm (23) and pucks (22).

Discard the pucks.

4. Remove the bypass arm retaining ring (18) and bypass arm (17). Discard the retaining ring.

5. If necessary, remove and replace the control arm stop stud (21).

Inspection

CONTROL ARM AND BYPASS ARM

Assembly

1. Install the bypass arm (17) onto the bypass rod. Secure the bypass arm with a new retaining ring (18).

2. Replace the control arm stop stud (21) if removed. Torque according to specifications in Table 6 on page 14.

3. Install the control arm (23).

4. Install the control arm screw (25). Refer to

Table 6 for screw torque specifications.

1. Inspect the control arm stop stud (21) for wear or damage.

2. Inspect the control arm (23) for wear or damage.

3. Inspect the bypass arm (17) for wear or damage.

310-2200 EZT ®

Figure 6. Control Arm and Bypass Arm

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SEAL KIT REPLACEMENT

Before disassembly, wipe the unit free of any debris to avoid contamination.

Refer to Figure 7.

Input Seal

1. Remove the input pulley from the input shaft.

2. Remove the seal retaining ring (34).

3. Carefully pull the input seal (33) out of the housing bore with a “hook” type tool. Care must be taken to avoid damage to the housing bore or shaft sealing area.

4. Lubricate the new seal with petroleum jelly prior to installation.

5. Wrap the shaft keyway (splines) with cellophane to prevent damage to the seal lip during installation.

6. Slide the seal over the shaft and press it into the housing bore.

7. The seal should seat against the spacer.

8. Install the seal retaining ring (34) and make sure it is fully seated in its groove.

Output Seal

1. The seal (51) can be replaced by following steps 2-6 of the procedure used to replace the input seal.

2. Install the retaining ring (34) and make sure it is fully seated in its groove.

Motor Shaft Seal

1. Remove the cog brake. See page 17.

2. The seal (10) can be replaced by following steps 3-6 of the procedure used to replace the input shaft.

Trunnion Seal

1. Remove the control arm and any attachments to the control arm. See page 15.

2. The seal (20) can be replaced by following steps 3-6 of the procedure used to replace the input shaft.

Bypass Seal

1. Remove the bypass arm and any attachments to the bypass arm. See page 15.

2. Remove the seal retaining ring (16). Remove the bypass rod, keeping the retaining ring

(14) attached. Remove the bypass rod seal

(13). Deburr the bypass rod.

3. Install the seal (13). Install the bypass rod with the retaining ring (14) attached. Install the seal retaining ring (16).

Figure 7. Seal Kit Replacement

16

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Refer to Figure 8.

Disassembly

1. Remove the control arm and bypass arm. See page 15.

2. Remove the oil from the transaxle. See page

9.

3. Remove the brake arm assembly (55), retaining ring (14) and cog brake disc (100).

COG BRAKE AND SIDE HOUSING

2. Check for excessive looseness at the arm pivot point.

3. Inspect the bearing and bushing areas in the side housing.

Assembly

1. Apply a bead of sealant around the perimeter of the side housing face. See sealant pattern on page 27.

2. Install the locating pins (8), if not already installed.

4. Remove the lip seal (10).

5. Remove the housing screws (9).

6. Pull the side housing (2), leaving the axle

(49) and bull gear (46) assembled in the main housing. It may be necessary to use screwdrivers at the pry points to break loose the sealant (positions H-L and M-P, Figure 8).

7. Clean off all the old sealant on the side and main housings. Take care not to damage the sealing surfaces. A wire brush and solvent is effective.

Inspection

3. Install the side housing (2). Use care not to smear the sealant bead.

4. Install the side housing screws (9). Refer to the screw tightening pattern in Figure 8 and torque specification in Table 6 on page 14.

5. Install the remaining seals. Refer to page 16.

Remember to use a seal protector during installation.

6. Install the brake disc (100), retaining ring

(14) and brake arm assembly (55).

7. Fill the transaxle with new oil. See page 9.

1. Check the brake arm brake disc for excessive wear or teeth damage. Replace if necessary.

8. Install the bypass arm and control arm. See page 15.

310-2200 EZT ®

Figure 8. Cog Brake and Side Housing Assembly

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AXLE SHAFT, REDUCTION GEARS AND EXPANSION PLATE

Refer to Figure 9.

Disassembly

3. Inspect the axle shaft, bearing and bushing.

4. Inspect the expansion plate.

1. Remove the bypass arm and control arm. See page 15.

Assembly

2. Remove oil from the transaxle. See page 9.

3. Remove the side housing. See page 17.

1. Apply a small bead of sealant to the expansion plate area of the housing. See page 27.

Install the expansion plate (53). Torque the screws according to Table 6.

4. Remove the spiral retaining ring (45), bull gear (46), inboard sleeve bearing (48) and washer (47).

2. Reassemble and install the reduction gears

(42 & 43), jack shaft pin (44) and washers

(41).

5. Remove the reduction gears (42 &43), jack shaft pin (44) and washers (41).

6. Remove seal retaining ring (34), seal (51), axle (49) and bushing (50).

3. Install the bull gear (46), retaining ring (45), bearing (48) and washer (47) onto the axle

(49).

7. If necessary, remove the expansion plate assembly (53).

4. Install the axle (49) and bushing (50) into the housing (1).

5. Install the axle seal (51) and retaining ring

(34).

NOTE: Expansion plate removal will typically destroy the plate. Clean all sealant from the expansion plate area.

6. Install the side housing. See page 17.

7. Install all remaining seals. See page 16.

Inspection

8. Fill the transaxle with oil. See page 9.

1. Inspect the bull gear for wear or damage.

2. Inspect the reduction gears, jack shaft pin and washers.

9. Install the bypass arm and control arm. See page 15.

18

Figure 9. Axle Shaft, Reduction Gears and Expansion Plate

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Refer to Figure 10.

Disassembly

1. Remove the control arm and bypass arm. See page 15.

2. Drain the oil from the transaxle. See page 9.

3. Remove the side housing. See page 17.

4. Remove the reduction gears. See page 18.

5. Remove flat washer (36), motor shaft and pinion gear (39 & 38) and flat washer (40).

Inspection

1. Inspect the motor shaft (39), pinnion gear (38) and flat washers (36 & 40) for wear or damage.

MOTOR SHAFT

Assembly

1. Insert the motor shaft (39) with the pinnion gear (38) and flat washers (36 & 40) into the center section (57).

2. Install the reduction gears. See page 18.

3. Install the side housing. Refer to page 17.

4. Install new seals. Refer to page 16.

5. Fill the transaxle with oil. See page 9.

6. Install the bypass arm and control arm. See page 15.

310-2200 EZT ®

Figure 10. Motor Shaft

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INPUT SHAFT AND BYPASS ROD

Refer to Figure 11.

Disassembly

5. Deburr the end of the bypass rod. Install the bypass rod (15), retaining ring (14), seal (13) and retaining ring (16).

1. Remove the control arm and bypass arm. See page 15.

6. Install the motor shaft. See page 19.

7. Install the reduction gears. See page 18.

2. Drain the oil from the transaxle. See page 9.

8. Install the side housing. See page 17.

3. Remove the side housing. See page 17.

4. Remove the reduction gears. See page 18.

9. Install new seals in the side housing. See page 16.

5. Remove the motor shaft. See page 17.

10. Fill the transaxle with oil. See page 9.

6. Remove the retaining ring (34) and shaft seal

(33). Discard the seal.

11. Install the bypass arm and control arm. See page 15.

7. Remove the spacer (32) and input shaft assembly (29, 30 & 31).

8. Remove the compression spring (27) and washer (28).

9. Remove the rings (14 & 16), bypass rod (15) and seal (13).

Inspection

1. Inspect the input shaft components and bypass rod for wear or damage.

Assembly

1. Visually ensure that the pump block is aligned concentrically with the center section running face.

2. Install the compression spring (27) and washer (28).

3. Insert the input shaft (29), with bearing (30) and retaining ring (31), into the pump block assembly. NOTE: Do not force the shaft and bearing as damage may occur. If alignment is correct, the shaft assembly will fit into place.

4. Install the washer (32), seal (33) and retaining ring (34). Use a seal protector when installing the input shaft seal.

Figure 11. Input Shaft and Bypass Rod Assembly

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Refer to Figures 12-21.

Disassembly

1. Remove the bypass arm and control arm. See page 15.

2. Drain the oil from the transaxle. See page 9.

3. Remove the side housing. See page 17.

4. Remove the reduction gears. See page 18.

5. Remove the motor shaft. See page 19.

6. Remove the input shaft and bypass rod. See page 20.

7. (See Figure 12) Remove the swashplate

(19) and pump cylinder block (4) as one assembly. NOTE: Removal will be aided by applying a small amount of pressure on the trunnion mounted swashplate towards the center section. Also note that the control arm (23, page 28) may be loosely assembled at this point to assist in swashplate removal. While gently removing the swashplate and block assembly, keep the block face flush with the center section to minimize damage to the running surface.

8. (See Figure 13) Disassemble the pump cylinder block (4) from the swashplate (19).

9. (See Figure 14) Check each piston for proper operation by pressing the pistons in and releasing them in the block bore. Disassemble the pump cylinder block. Check for piston/block wear in the cylinder bore. Inspect the pistons (A), piston springs (C) and thrust washers (B) for excessive wear or damage.

NOTE: Thrust washers may be held in place in the piston by residual oil.

10. Reassemble the pistons, springs and washers into the cylinder block and set aside.

11. (See Figure 15) Remove the thrust bearing assembly (35) from the swashplate (19).

HYDRAULIC COMPONENTS

(Center Section/Filter)

12. (See Figure 16) Remove the center section mounting screws (12). NOTE: The center section is under motor block piston spring pressure. These screws are factory installed to 700 lb-in (80 Nm) and use an anaerobic thread adhesive. A breaker bar will be required at this step. Clean the internal threads of the mounting holes with compressed air.

13.Remove the center section and filter assembly (57, Figure 17). NOTE: Bypass plate (Figure 17) may slide out of the center section.

14. Remove the filter cover by pressing in and down on the filter cover tabs. Discard the cover.

15.Note the location of both check plugs (56) before removal for correct replacement during reassembly. Remove and inspect the check plug assemblies (56) for debris or damage.

16.Remove the filter base (61) and discard it.

NOTE: The filter base is included in the filter kit to be installed during reassembly of the unit.

(Motor Block)

17. (See Figure 19) Remove the motor cylinder block assembly (4) from the housing (1).

18.Disassemble the motor cylinder block assembly (4). Check each piston for proper operation by pressing the pistons in and releasing them in the block bore. Disassemble the motor cylinder block. Check for piston/ block wear in the cylinder bore. Inspect the pistons, piston springs and thrust washers for excessive wear or damage. NOTE:

Thrust washers may be held in place in the piston by residual oil.

19.Reassemble the pistons, springs and thrust washers into the cylinder block and set aside.

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20. Remove the thrust bearing assembly (35) from the housing (1). Inspect the thrust bearing and thrust bearing cavity in the housing.

Inspection

1. Inspect the pump cylinder block running surface for wear or damage.

2. Inspect the swashplate and thrust bearing assemblies for wear or damage.

3. Inspect the center section block running surfaces. NOTE: These “sealing” surfaces should be smooth in appearance without scratches, scoring, nicks or abrasions. Drag a fingernail across the surface to detect uneven wear or scratches which may not be visible.

4. Inspect the threaded check plug ports of the center section for debris or damage.

5. Inspect the motor cylinder block running surface for damage and wear.

6. Inspect all bearing, bushing and wear areas in the housing.

Assembly

(Motor Block)

1. (See Figure 19) Turn the housing (1) so the motor thrust bearing cavity is facing up. This will assist in the installation of the motor thrust bearing assembly (35) keeping it in the bearing cavity during installation of the center section assembly (57, Figure 17).

2. Insert the thrust bearing (35) in the housing

(1). NOTE: Place the thin race of the bearing towards the housing bearing cavity. The thick race must face the pistons.

(Center Section/Filter)

3. (See Figure 18) Install the new filter base (61) onto the center section (57).

4. It will be necessary to clean the check plugs prior to re-assembly. Install the check plugs

(56), in their correct location, into the center section (57). Tighten the check plugs according to Table 6.

5. Align the tabs on the filter cover with the slots in the filter base and carfully press the cover onto the base until the tabs snap into place. Insure the bypass plate (Figure 18) is located properly in the center section.

6. (See Figures 10 & 20) Install the motor shaft

(39), pinion gear (38) and flat washers (36 &

40) into the center section (57).

7. Assemble the motor block assembly (4) onto the motor shaft (39).

8. (See Figure 20) Install the motor shaft, center section and motor block assembly into the housing so that the motor block pistons contact the thrust bearing race. NOTE: Hold in place and insure all pistons are still positioned correctly in the cylinder bore by confirming spring bias against the center section.

9. (See Figure 16) After applying thread adhesive, insert the center section mounting screws (12) while holding downward pressure on the center section assembly (57,

Figure 20).

10. Tighten the center section mounting screws

(12) to the proper torque. Refer to Table 6.

NOTE: The center section must be fully seated into the pilot bore before the screws are tightened. The center section will not self

22

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(Swashplate/Pump Block)

11. (See Figure 15) Install the pump thrust bearing (35) in the trunnion machined swashplate

(19). NOTE: Place the thin race of the bearing towards the swashplate. The thick race must face the pistons.

12. (See Figure 13) Place the pump block assembly (4), pistons down, on top of the thrust bearing in the swashplate (19).

13.Coat the pump running surface with clean motor oil.

14.Care must be taken to prevent the scaring

or scratching of the center section sealing

face during this step. Insert the shaft of the swashplate/pump block assembly (Figure

21) into the housing while simultaneously compressing the pistons in the block. NOTE:

To assist in the installation of these components, insert the assembly until 3/4 of the pump block is covered by the center section.

Then slightly press the shaft end toward the center section while pushing the shaft into its bore.

15. Install the input shaft and bypass rod. See page 20.

16. Install the axle shaft, reduction gears and expansion plate, if removed. Refer to page 18.

17. Install the side housing and brake. See page

17.

18. Fill the transaxle with new oil. See page 9.

19. Install the bypass arm and control arm. See page 15.

Figure 12.

Figure 13.

310-2200 EZT ®

Figure 14.

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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

Figure 15.

Figure 18.

Figure 16.

Figure 19.

24

Figure 17.

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TRANSAXLE INSTALLATION

Use the following procedure to complete the installation of the transaxle on the vehicle.

1. Install and secure the transaxle on the vehicle according to the instructions in the vehicle owner’s manual.

2. With the vehicle raised, install the wheels on the axles, and snug the wheel hardware.

3. Lower the vehicle wheels to the ground and torque the wheel hardware per the vehicle owner’s manual.

Figure 20.

Figure 21.

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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

ASSEMBLY AFTER A COMPLETE TEARDOWN

If the unit has been torn down completely, the following summary identifies the assembly procedures necessary to completely assemble the unit. 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 on page 26.

1. Install the hydraulic components. See pages 21-25.

2. Install the input shaft and bypass rod. See page 20.

3. Install the axle shaft, reduction gears and expansion plate. See page 18.

4. Install the cog brake and side housing.

See page 17.

5. Fill the transaxle with new oil. See page 9.

6. Install the bypass arm and control arm.

See page 15.

7. Install the transaxle onto the vehicle.

8. Perform the purge procedures listed on page 10.

26

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SEALANT APPLICATION

NOTE: Prior to applying the new sealant, the

old sealant must be removed from all surfaces.

A small consistent bead of the sealant around the housing face will be sufficient. Use sparingly.

The illustration below indicates the correct areas.

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Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

310-2200 EXPLODED VIEW

28

Figure 22. 310-2200

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17

18

19

20

21

13

14

15

16

8

9

10

12

5

6

7

28

29

30

31

22

23

24

25

26

27

36

37

38

39

40

32

33

34

35

41

42

43

44

45

46

No.

1

2

3

4

DESCRIPTION

ASSEMBLY, MAIN HOUSING

HOUSING, MAIN

BUSHING, .865 X .985 X.790

PLATE, EXPANSION

SCREW, 10-32 X 1/2 (SELF TAPPING)

PIN, STANDARD, HEADLESS

SEAL, LIP .375 X .75 X .25

ASSEMBLY, SIDE

HOUSING, SIDE

BUSHING, .624 X .719 X .562

BUSHING, .865 X .985 X .790

PLATE, BYPASS

ASSEMBLY, PUMP BLOCK

BLOCK, CYLINDER

PISTON

SPRING, COMPRESSION

WASHER, THRUST

SPACER

ASSEMBLY, MOTOR BLOCK

PLUG, 9/16-18

PIN, STAINLESS, HEADLESS

HFHCS 1/4-20 X 1.25 (SELF-TAPPING)

SEAL, LIP .625 X 1.000 X .250

BOLT, HEX FLANGE 3/8-24 X 2.5

SEAL, LIP .375 X .75 X .25

RING, RETAINING .375 EXT

ROD, BYPASS

RING, RETAINING .750 INT

ARM, BYPASS

RING, RETAINING .375 EXT (PUSHNUT)

SWASHPLATE, TRUNNION, MACHINED

SEAL, LIP 18 X 32 X 7

STUD

PUCK, FRICTION

ARM, CONTROL

WASHER, FLAT 11/32 ID X 7/8 OD X 1/16

TWHCS 5/16-24 X 1.0

NUT, HEX LOCK 5/16-24 UNJF

SPRING-HELICAL COMPRESSION

WASHER .591 X .787 X .040

SHAFT, INPUT

BEARING, BALL 17MM ID X 40MM OD X 12MM

RING, RETAINING WIRE .561 ID

SPACER

SEAL, LIP 17 X 40 X 7

RING, RETAINING

BEARING, THRUST 30 X 52 X 13

WASHER, FLAT 5/8 ID X 1.0 OD X .05

RING, RETAINING

GEAR, PINION, 13T

SHAFT, MOTOR

WASHER, MOTOR SHAFT .71 ID X 1.16 OD X .04

WASHER, HT .5 ID X 1.0 OD X .032

GEAR, 10T/48T

GEAR, 10T JACKSHAFT

PIN, JACKSHAFT

RING, SPIRAL RETAINING

GEAR, 52T BULL

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No.

47

48

49

50

51

52

53

54

55

56

57

59

61

134

135

136

137

138

140

141

142

143

144

124

125

126

127

128

131

132

133

99

100

120

121

122

123

310-2200 ITEMS LIST

DESCRIPTION

WASHER, 3/4 ID X 1-1/2 OD X .13

BEARING, SLEEVE (INBOARD)

AXLE

BUSHING, .752 X 1.571 X .625

SEAL, LIP .750 X 1.577 X .250

KIT, SEAL

KIT, EXPANSION PLATE

PLATE EXPANSION

SCREW, 10-32 X 1/2 (SELF-TAPPING)

KIT, FAN-PULLEY

KIT, BRAKE ARM

ARM, PARKING BRAKE

WASHER .28 X .50 X .063

BOLT, 1/4-20 X 1 W/PATCH

BUSHING, .260 X .394 X .330

PIN, CLEVIS

CHECK PLUGS

KIT, CENTER SECTION-FILTER

CENTER SECTION, MACHINED

BUSHING, .707 X .788 X .591

PLATE, BYPASS

BOLT, HEX FLANGE 3/8-24 X 2.5

FILTER, BASE

CHECK PLUG ASSEMBLY

ASSEMBLY, COVER

ASSEMBLY, PUMP BLOCK

KIT, BYPASS ARM

ARM, BYPASS

RING, RETAINING .375 EXT (PUSHNUT)

KIT, FILTER

FILTER, BASE

ASSEMBLY, COVER

NUT, HEX 3/4-16 LOCK

DISC, COG BRAKE

FAN, 10 BLADE

PULLEY

HEX LOCK NUT, 1/2-20 (NYLON INSERT)

WASHER, OD SLOTTED

HEX WASHER HEAD TAPPING SCREW 1/4-20 X .25

ASSEMBLY, HUB, 4 STUD, 1/2-20 (30° TAPER)

CAP, VENT ASSEMBLY

FITTING, O-RING ASSEMBLY

CLAMP, PINCH, SINGLE EAR

FITTING

SHCS, 5/16-24 X 1.00 (PATCH)

BUSHING, PILOT, 1.125

WASHER, PLASTIC

WASHER, 1.5 X .34 X .062

SPRING, EXTENSION

KIT, RTN ASSEMBLY

HOSE

KIT, BREATHER ASSEMBLY

PUCK, FRICTION

SPACER, FRICTION PUCK

SPACER, .320 X .590 X .500

SPRING, HELICAL COMPRESSION

DEFLECTOR, BELT

29

Hydro Gear Parts or New Units Call 606-678-9623 or 606-561-4983

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 mechanically generated 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”

Hydrostatic Transaxle: A multicomponent assembly including a gear case and a hydrostatic transmission.

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Hydrostatic Transmission: The combination of a hydraulic pump and motor in one housing to form a device for the control and transfer of power.

Inlet Line: A supply line to the pump.

Integrated Zero-Turn Transaxle: 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 efficiency losses.

Valve: A device which controls fluid flow direction, pressure, or flow rate.

Variable Displacement Pump: A pump in which the displacement per revolution can be varied.

Volumetric Displacement: The volume for one revolution.

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NOTES

32

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NOTES

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33

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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®