Hydro-Gear EZT ZC & ZD Zero-Turn Transaxle Service and Repair Manual
تبلیغات
تبلیغات
EZT
®
Integrated Zero-Turn Transaxle
Service and Repair Manual
(ZC & ZD Models)
BLN-52622
October 2009
TablE of ConTEnTS
Section Page
foreword .............................................................................................................................. 1
Description and operation ................................................................................................. 2
Introduction .................................................................................................................................................. 2
General Description ..................................................................................................................................... 2
Hydraulic Schematic .................................................................................................................................... 3
External Features -EZT
®
......................................................................................................................... 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 ................................................................................................................................. 12
How To Use This Section ........................................................................................................................... 12
General Instructions ................................................................................................................................... 12
Transaxle Removal .................................................................................................................................... 12
Limited Disassembly .................................................................................................................................. 12
Tools and Torques ...................................................................................................................................... 13
Control Arm and Bypass Arm ..................................................................................................................... 14
Hub Replacement ...................................................................................................................................... 15
Seal Kit Replacement ................................................................................................................................ 16
Cog Brake Assembly .................................................................................................................................. 17
Disc Brake Assembly ................................................................................................................................. 18
Side Cover ................................................................................................................................................ 19
Axle Shaft, Reduction Gears and Expansion Plate .................................................................................... 20
Motor Shaft ................................................................................................................................................ 21
Input Shaft and Bypass Rod ...................................................................................................................... 22
Hydraulic Components .......................................................................................................................... 23-27
Transaxle Installation ................................................................................................................................. 27
Assembly After a Complete Teardown ....................................................................................................... 28
Sealant application ........................................................................................................... 29
Parts list ...................................................................................................................... 31, 30
Glossary of Terms ....................................................................................................... 33, 34
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 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 OPEESA (Outdoor Power Equipment and Engine Service Association) at (860)
767-1770 or their Hydro-Gear Central Service
Distributor. Many distributors will be hosting certification testing. These study guides will cover most of the products and manufacturers in our industry.
For more information about Hydro-Gear or our products, please contact your Central Service
Distributor, or call our Customer Service Department at (217) 728-2581.
EZT
®
1
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 EZT 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 EZT 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 EZT 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
EZT
®
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 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 increase and cause a
figure 2. Hydraulic flow illustration
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 EZT 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.
EZT
®
3
EXTErnal fEaTurEs EZT
®
AXLE SHAFT
MAIN HOUSING
BYPASS ARM
4
FILL PORT
INPUT SHAFT
CONTROL ARM
SIDE COVER
BRAKE ARM
FAN
PULLEY
COG BRAKE DISC
AXLE SHAFT
EZT
®
TEcHnical spEcificaTions
Technical specifications for the EZT
®
are listed in Table 1.
input speeds
Maximum: 3000 RPM
Minimum: 1800 RPM
Table 1. Technical Specifications weight of unit
29 lbs. (13 Kg)
Table 2. EZT component options component axle shaft diameter and End options:
Brake location:
Brake Type: control arm location: control arrangements: overall Transaxle reduction: component options
1˝ Flange
Inboard
Cog
Inboard
Standard Control Arm
19.2:1
1˝ DD
Outboard
Disc
Outboard
RTN (scissor style)
21.2:1
producT idEnTificaTion
The model and configuration of the EZT can be determined from the label shown in Figure 3.
EZT
®
Figure 3. Configuration Label
5
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 EZT section.
®
, fully read and understand the safety precautions described in this
pErsonal safETY
Certain safety precautions must be observed while servicing or repairing the 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.
6 EZT
®
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 EZT
®
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. 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 21
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, Pages 2 and 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
EZT
®
7
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 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 EZT 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. The unit should be thoroughly cleaned before any service procedures are performed.
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 for the proper fill port location.
Fill the EZT 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.
8 EZT
®
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.
noTE: if removing the wheel from the transaxle, do so by removing the four (4)
lug nuts. do not remove the axle/hub nut.
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.
fluid description
20W50 engine oil
Table 4. fluid volumes for the EZT
® volume
52.4 fl. oz. (1550 ml) to 55.8 fl. oz. (1650 ml)
TOP OF FILL PORT
0.75” - 1.50” (19-38mm) depth at 50°-100°F (10°-38°C)
OIL LEVEL
figure 4. fluid level and fill port
EZT
®
9
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 EZT
®
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 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 wheel from the axle hub to access the linkage control and the transaxle return arm. remove the wheel by removing the four (4) lug nuts. do not remove the axle/hub nut.
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
AXLE ROTATION “A”
AXLE
ROTATION
“B”
AXLE
ROTATION
“A”
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.
full engine speed.
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.
AXLE ROTATION “B”
15°
15°
RTN Adjustment Screw
Speed and Directional Control
figure 5. return to neutral setting
EZT
®
11
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 31 for part names and descriptions. 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
® found in BLN-51427 (CD).
replacement parts
iMporTanT: When internal repair is performed on the EZT
®
, the filter assembly must be replaced.
TransaXlE rEMoval
It is necessary to remove the EZT from the vehicle before performing the repair procedures presented in this section.
noTE: if removing the wheel from the transaxle, do so by removing the four (4)
lug nuts. do not remove the axle/hub nut.
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 27.
12 EZT
®
Miscellaneous
EZT
®
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
Tools and TorQuEs
Table 5. required Tools 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
Metal Plug
Side Housing Screws
Center Section Bolts
Control Arm Stop Stud
Control Arm Screw
Stop Stud Nut
Check Plugs
Expansion Plate Screws
Brake Assembly Screw
Hub Locknut
Fan/Pulley Lock Nut
Breather Fitting
RTN Adjustment Screw
Disc Brake Screw
Table 6. required Torque values
Torque
180-240 lb-in [20-27 Nm]
105-155 lb-in [12-17 Nm]
525-700 lb-in [60-80 Nm]
50-120 lb-in [6-18 Nm]
230-310 lb-in [26-35 Nm]
85-120 lb-in [10-14 Nm]
280-400 lb-in [32-45 Nm]
25-50 lb-in [3-6 Nm]
80-120 lb-in [9-14 Nm]
240-260 lb-ft [271-298 Nm]
360-520 lb-in [41-59 Nm]
180-240 lb-in [20-27 Nm]
175-200 lb-in [19-22 Nm]
80-120 lb-in [9-14 Nm]
item
25
26
56
65
7
9
12
21
73
99
122
126
131
157
description
Plug 9/16-18
Screw 1/4-20 x 1.25
Screw 3/8-24 x 2.5
Stud 5/16-24
Screw 5/16-24 x 1
Nut, Lock 5/16-24 UNF
Check Plug Assembly
Screw 10-32 x 0.50
Screw 1/4-20 x 1
Nut, Hex 3/4-16 Lock
Lock Nut 1/2 x 20
Fitting 9/16
Screw 5/16-24 x 1
Screw 1/4-20 x 2
EZT
®
13
conTrol arM and BYpass arM
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
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.
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 13.
3. Install the control arm (23).
4. Install the control arm screw (25). Refer to
Table 6 for screw torque specifications.
14 figure 6. control arm and Bypass arm
EZT
®
wHEEl HuB and nuT
Refer to Figure 7.
disassembly
noTE: This procedure is only necessary if your unit is equipped with a pin locking nut
(Figure 7a).
1. Place the axle so that the pin lock is at the
9 o’clock position.
2. Place a punch on the pin lock of the nut
(99)
3. Tap on the end of the punch with a rubber mallet until the pin lock moves off of the shaft.
4. Remove and discard the pin locking nut.
5. Remove the hub (124)
assembly
1. Install hub (124) onto the shaft.
2. Install nut (99) onto shaft. Torque according to specifications in Table 6 on page 13.
figure 7a. pin locking nut.
inspection
1. Inspect the hub and axle splines for any damage
Punch
99
124
Pin Lock
figure 7b. pin locking nut removal.
EZT
®
15
Before disassembly, wipe the unit free of any debris to avoid contamination.
Refer to Figure 8.
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 brake assembly. See pages
17-18.
2. The seal (10) can be replaced by following steps 3-6 of the procedure used to replace the input shaft.
sEal KiT rEplacEMEnT
Trunnion seal
1. Remove the control arm and any attachments to the control arm. See page 14.
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 14.
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 8. seal Kit replacement
16 EZT
®
cog BraKE assEMBlY
Refer to Figure 9.
disassembly
1. Remove the control arm and bypass arm.
See page 14.
2. Remove the oil from the transaxle. See page
9.
3. Remove the brake arm spring (75), if installed. Remove the brake arm screw(s)
(73), washer(s) (72), brake arm (74) and bushing(s) (71).
4. Remove the retaining ring (14) and cog brake disc (100).
5. Remove the motor shaft lip seal (10), if removing the side housing.
inspection
1. Check the brake arm and cog brake disc for excessive wear or teeth damage. Replace if necessary.
2. Check for excessive looseness at the arm pivot point.
assembly
1. Install the motor shaft lip seal (10), if removed. Refer to page 16. Remember to use a seal protector during installation.
2. Install the cog brake disc (100) and retaining ring (14).
3. Install the bushing(s) (71), brake arm (74), washer(s) (72) and brake arm screw(s) (73).
Torque screws to 80-120 in-lbs (9-14 Nm).
4. Install the brake arm spring (75), if removed.
5. Fill the transaxle with new oil. See page 9.
6. Install the bypass arm and control arm. See page 14.
EZT
®
100
14
74
71
75
73
72
73
72
71
10
figure 9. cog Brake assembly
17
Refer to Figure 10.
disassembly
1. Remove the control arm and bypass arm.
See page 14.
2. Remove the oil from the transaxle. See page
9.
3. Remove the brake arm bias spring (75).
4. Remove the cotter pin (160), castle nut (159) and washer (158).
5. Remove the brake arm (74), compression spring (156) and two brake pins (155).
6. Remove the brake yoke assy screws (73
& 157), the spacer (154), brake yoke assy
(153), puck plate (151), outer puck (150), rotor (100) and inner puck (150).
7. Remove the motor shaft lip seal (10), if removing the side housing.
inspection
1. Check the brake disc and pucks for excessive wear. Replace if necessary.
disc BraKE assEMBlY
2. Check for excessive looseness at the arm pivot point.
assembly
1. Install the motor shaft lip seal (10), if removed. Refer to page 16. Remember to use a seal protector during installation.
2. Install the inner puck (150), rotor (100), outer puck (150) and puck plate (151).
3. Install the brake yoke assy (153), brake pins
(155), spacer (154) and the brake yoke assy screws (73 & 157).
4. Install the compression spring (156), the brake arm (74), the washer (158), the castle nut (159) and the cotter pin (160).
5. Install the brake arm bias spring (75).
7. Fill the transaxle with new oil. See page 9.
8. Install the bypass arm and control arm. See page 14.
18
160
74
157
75
158
159
100
154
153
151
73
153
2X 155
156
10
2X 150
figure 10. disc Brake assembly
EZT
®
sidE covEr
Refer to figure 11.
disassembly
1. Remove the control arm and bypass arm.
See page 14.
2. Remove the oil from the transaxle. See page
9.
3. Remove the brake assembly. See pages 16 and 17.
4. Remove the motor shaft lip seal. See page
16.
5. Remove the side housing screws (9) and belt deflector (144), if installed.
6. Pull the side housing (68), leaving the axle
(49) and bull gear (46) assembled in the main housing. It may be necessary to use pry tools at the pry points to break loose the sealant (positions 1-16 and 4-6, Figure
11).
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
1. Inspect the bearing and bushing areas of the side cover.
assembly
1. Apply a bead of sealant around the perimeter of the side housing face. See sealant pattern on page 28.
2. Install the locating pins (8), if not already installed.
3. Install the side housing (2). Use care not to smear the sealant bead.
4. Install the side housing screws (9) and belt deflector (144, if used). Refer to the screw tightening pattern in Figure 11 and torque specification in Table 6 on page 13.
5. Install the remaining seals. Refer to page
16. Remember to use a seal protector during installation.
6. Install the brake assembly. See pages 17 and 18.
7. Fill the transaxle with new oil. See page 9.
8. Install the bypass arm and control arm. See page 14.
16X 9
EZT
®
68
144
2X 8
66
1
16
3
5
figure 11. side cover
14
12
10
8
6
7
9
11
13
15
4
2
19
aXlE sHafT, rEducTion gEars and EXpansion plaTE
Refer to Figure 12.
disassembly
3. Inspect the axle shaft, bearing and bushing.
4. Inspect the expansion plate.
1. Remove the bypass arm and control arm.
See page 14.
assembly
2. Remove oil from the transaxle. See page
9.
3. Remove the side cover. See page 19.
1. Apply a small bead of sealant to the expansion plate area of the housing. See page 29.
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).
7. If necessary, remove the expansion plate assembly (53).
3. Install the bull gear (46), retaining ring (45), bearing (48) and washer (47) onto the axle
(49).
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 cover. See page 19.
7. Install all remaining seals. See page 16.
inspection
1. Inspect the bull gear for wear or damage.
8. Fill the transaxle with oil. See page 9.
2. Inspect the reduction gears, jack shaft pin and washers.
9. Install the bypass arm and control arm. See page 14.
20 figure 12. axle shaft, reduction gears and Expansion plate
EZT
®
MoTor sHafT
Refer to Figure 13.
disassembly
1. Remove the control arm and bypass arm.
See page 14.
2. Drain the oil from the transaxle. See page
9.
3. Remove the side cover. See page 19.
4. Remove the reduction gears. See page
20.
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.
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 20.
3. Install the side cover. Refer to page 19.
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 14.
EZT
® figure 13. Motor shaft
21
Refer to Figure 14.
disassembly
1. Remove the control arm and bypass arm.
See page 14.
2. Drain the oil from the transaxle. See page
9.
3. Remove the side cover. See page 19.
4. Remove the reduction gears. See page
20.
5. Remove the motor shaft. See page 21.
6. Remove the retaining ring (34) and shaft seal (33). Discard the seal.
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
22
inpuT sHafT and BYpass rod
installing the input shaft seal.
5. Deburr the end of the bypass rod. Install the bypass rod (15), retaining ring (14), seal (13) and retaining ring (16).
6. Install the motor shaft. See page 21.
7. Install the reduction gears. See page 20.
8. Install the side cover. See page 19.
9. Install new seals in the side housing. See page 16.
10. Fill the transaxle with oil. See page 9.
11. Install the bypass arm and control arm. See page 14.
figure 14. input shaft and Bypass rod assembly
EZT
®
HYdraulic coMponEnTs
Refer to Figures 15-24.
disassembly
1. Remove the bypass arm and control arm.
See page 14.
2. Drain the oil from the transaxle. See page
9.
3. Remove the side cover. See page 19.
4. Remove the reduction gears. See page
20.
5. Remove the motor shaft. See page 21.
6. Remove the input shaft and bypass rod. See page 22.
7. (see figure 15) 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 31) 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 16) Disassemble the pump cylinder block (4) from the swashplate (19).
9. (see figure 17) 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 18) Remove the thrust bearing assembly (35) from the swashplate (19).
(center section/filter)
12. (see figure 19) 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 20). NOTE: Bypass plate (Figure 21) 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 22) Remove the motor cylinder block assembly (6) 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.
EZT
®
23
19. Reassemble the pistons, springs and thrust washers into the cylinder block and set aside.
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 22) 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 20).
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.
HYdraulic coMponEnTs
(center section/filter)
3.
(see figure 21) 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 21) is located properly in the center section.
6.
(see figures 13 & 23) Install the motor shaft (39), pinion gear (38) and flat washers
(36 & 40) into the center section (57).
7. Assemble the motor block assembly (6) onto the motor shaft (39).
8.
(see figure 21) 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 19) After applying thread adhesive, insert the center section mounting screws (12) while holding downward pressure on the center section assembly (57,
Figure 23).
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 locate.
24 EZT
®
(swashplate/pump Block)
11.
(see figure 18) 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 16) 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
24) 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 22.
16. Install the axle shaft, reduction gears and expansion plate, if removed. Refer to page
20.
17. Install the side cover and brake. See pages
17-19.
18. Fill the transaxle with new oil. See page
9.
19. Install the bypass arm and control arm. See page 14.
EZT
® figure 15.
figure 16.
A
B
C
4
19
35
figure 17.
25
26 figure 18.
figure 19.
1
figure 21.
35
figure 22.
6
figure 20.
EZT
®
TransaXlE insTallaTion
1
6
19
57
39
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.
4
38
figure 23.
figure 24.
EZT
®
27
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.
3. Install the axle shaft, reduction gears and expansion plate. See page 20.
4. Install the cog brake and side cover. See page 17-19.
5. Fill the transaxle with new oil. See page 9.
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 30.
6. Install the bypass arm and control arm.
See page 14.
7. Install the transaxle onto the vehicle.
1. Install the hydraulic components. See pages 23-27.
8. Perform the purge procedures listed on page 10.
2. Install the input shaft and bypass rod. See page 22.
28 EZT
®
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.
EZT
®
29
noTEs
30 EZT
®
EZT
®
EXplodEd viEw
EZT
®
DISC BRAKE
figure 24. EZT
®
BRAKE KIT
MOUNT
TOP
CLEVIS PIN
BRAKE KIT
THROUGH HOLE
BRAKE KIT
W/ SPRING
BRAKE KIT
31
32 no.
dEscripTion
1 ASSEMBLY, MAIN HOUSING
2
3
4
BUSHING
ASSEMBLY, SIDE COVER
BUSHING
PLATE, BYPASS
ASSEMBLY, PUMP BLOCK
BLOCK, CYLINDER
PISTONS
SPRINGS, COMPRESSION
WASHERS, THRUST
SPACER
ASSEMBLY, MOTOR BLOCK
PLUG, 9/16-1
PIN, STAINLESS, HEADLESS
HFHCS 1/4-20 X 1.25 (SELF-TAPPING)
SEAL, LIP
BOLT, HEX FLANGE 3/8-24 X 2.5
SEAL, LIP
RING, RETAINING
ROD, BYPASS
RING, RETAINING
ARM, BYPASS
RING, RETAINING (PUSHNUT)
SWASHPLATE, TRUNNION, MACHINED
SEAL, LIP
STUD
WASHER
ARM, CONTROL
WASHER, FLAT
TWHCS 5/16-24 X 1.0
NUT, HEX LOCK 5/16-24 UNJF
SPRING-HELICAL COMPRESSION
WASHER
SHAFT, INPUT
BEARING, BALL
RING, RETAINING WIRE
SPACER
SEAL, LIP
RING, RETAINING
BEARING, THRUST
WASHER, FLAT
RING, RETAINING
GEAR, PINION, 13T
SHAFT, MOTOR
WASHER, MOTOR SHAFT
WASHER, HT
GEAR, 10T/48T
GEAR, 10T JACKSHAFT
PIN, JACKSHAFT
RING, SPIRAL RETAINING
GEAR, 52T BULL
WASHER
BEARING, SLEEVE (INBOARD)
AXLE
BUSHING
SEAL, LIP
KIT, SEAL
KIT, EXPANSION PLATE
KIT, FAN-PULLEY
43
44
45
39
40
41
42
35
36
37
38
32
33
34
50
51
52
46
47
48
49
53
54
28
29
30
31
25
26
27
21
22
23
24
18
19
20
14
15
16
17
10
12
13
5
8
9
6
7
EZT
®
iTEMs lisT
no.
dEscripTion
55 KIT, BRAKE ASSEMBLY
140
141
144
150
151
153
154
128
130
131
134
135
138
139
155
156
157
158
159
160
200
120
121
122
123
124
126
127
72
73
74
75
99
100
119
67
68
70
71
64
65
66
60
61
62
63
56
57
59
CHECK PLUGS
KIT, CENTER SECTION-FILTER
KIT, BYPASS ARM
ASSEMBLY, COVER
KIT, FILTER
FILTER, BASE
CENTER SECTION
MAGNET
SCREW, 10-32 X 1/2 (SELF-TAPPING)
HOUSING, MAIN
PLATE, EXPANSION
COVER, SIDE
PIN, CLEVIS
BUSHING
WASHER
SCREW
ARM, BRAKE
SPRING
NUT, PIN LOCKING
ROTOR
HUB
FAN
PULLEY
NUT, HEX LOCK
WASHER OR CAPSCREW 1/4-20
HUB KIT
FITTING
HOSE, EXPANSION TANK
CAP, BARBED VENT
NUT, HEX 1/4-20
SPACER OR CAPSCREW 5/16-20 X 1
WASHER
SPRING
KIT, BREATHER ASSEMBLY
KIT, BREATHER ASSEMBLY
ARM, NEUTRAL
RTN
DEFLECTOR, BELT
PUCK, BRAKE
PLATE, PUCK
ASSEMBLY, BRAKE YOKE
SPACER
PIN, BRAKE
SPRING, BRAKE COMPRESSION
CAPSCREW, 1/4-20 X 2.0
WASHER
NUT, CASTLE 5/16-24
PIN, COTTER
KIT, RTN
EZT
®
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.
EZT
®
33
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.
34 EZT
®
© 2009 Hydro-Gear
Printed in U.S.A.
Rev. P7
EZT
®
35
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