ZT-5400 Powertrain® Service and Repair Manual BLN-0014 May, 2018
TABLE OF CONTENTS Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . �������1 Side Housing. . . . . . . . . . . . . . . . . . . . . . . . . . . . �����24 Description and Operation . . . . . . . . . . . . . . . . . �������2 Axle Shaft And Planetary Gear Set . . . . . . . . . . �����25 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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.
DESCRIPTION AND OPERATION INTRODUCTION The purpose of this manual is to provide information useful in servicing the Hydro-Gear® ZT-5400 Powertrain® Hydrostatic Transaxle. This manual includes the ZT-5400 Powertrain’s general description, hydraulic schematic, technical specifications, servicing and troubleshooting procedures. Should 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.
DESCRIPTION AND OPERATION (CONTINUED) HYDRAULIC SCHEMATIC Figure 1 is a schematic of the hydraulic oil circuit. The oil supply for the hydraulic system of the ZT-5400 Powertrain® 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.
EXTERNAL FEATURES ZT-5400 POWERTRAIN® — Inboard View— OIL FILL VENT PORT CHARGE PUMP — Bottom View— 4 ZT-5400 Powertrain
EXTERNAL FEATURES ZT-5400 POWERTRAIN® EXPANSION TANK PORT/FILL PORT OIL FILL VENT PORT — Top View— INPUT SHAFT INPUT SHAFT RTN CONTROL ARM Control Arm Return to Neutral — Outboard View— ZT-5400 Powertrain 5
TECHNICAL SPECIFICATIONS ZT-5400 P owertrain ® TECHNICAL SPECIFICATIONS ZT-5400 Powertrain Reduction Package 0401 0402 Normal Speed 18.6:1 23.1:1 (Optional) 2 Speed 12.9:1 16.0:1 Overall Transaxle Reduction Input Speed Maximum 3600 rpm Minimum 1800 rpm Output Torque Intermittent 525 lb-ft (711 N-m) 650 lb-ft (880 N-m) Continuous 260 lb-ft (352 N-m) 325 lb-ft (440 N-m) Weight on Tires (per unit) Maximum with 23” tires 800 lb (362.8 kg) Maximum with 24” tires 800 lb (362.
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.
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 ZT-5400 Powertrain® are not related to a defective transaxle, but are caused by slipping drive belts, partially engaged bypass valves, and loose or damaged control linkages.
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 ZT-5400 Powertrain® should include the following: 1. Check the vehicle operator’s manual for the recommended load ratings. Insure the current application does not exceed load rating. 2.
FLUID CHANGE PROCEDURE This transaxle is designed with a serviceable filter. To ensure constant fluid quality levels and longer life, an initial oil and filter change at 100 hours is recommended. Subsequent changes are recommended at 400 hour intervals minimum, or yearly, whichever comes first. Oil Fill Volume (Fill to 100% capacity) The following procedure can be performed with the transaxle installed in the vehicle, and the vehicle on level ground.
PURGING PROCEDURES Due to the effects air has on efficiency in hydrostatic drive applications, it is critical that it be purged from the system. These purge procedures should be implemented any time a hydrostatic system has been opened to facilitate maintenance or any additional oil has been added to the system. Air creates inefficiency because its compression and expansion rate is higher than that of the oil approved for use in hydrostatic drive systems.
RETURN TO NEUTRAL SETTING WARNING POTENTIAL FOR SERIOUS INJURY Certain procedures require the vehicle engine to be operated and the vehicle to be raised off the ground. To prevent possible injury to the servicing technician and/or bystanders, insure the vehicle is properly secured. The return to neutral mechanism on the transaxle is designed to set the directional control into a neutral position when the operator removes their hand from the control lever.
2-SPEED OPTION SETTING WARNING POTENTIAL FOR SERIOUS INJURY Certain procedures require the vehicle engine to be operated and the vehicle to be raised off the ground. To prevent possible injury to the servicing technician and/or bystanders, insure the vehicle is properly secured. The 2-speed option mechanism on the transaxle is designed to increase the axle speed when the 2-speed control arm (168) is moved from its vertical position.
TEAR DOWN AND REASSEMBLY HOW TO USE THIS MANUAL Each subassembly illustrated in this section is illustrated by an exploded view showing the parts involved. The item reference numbers in each illustration are for assembly instructions only. See page 37 for part names and descriptions. A complete exploded view and item list of the transaxle is provided on pages 38 and 39. Many of the parts and subassemblies of this transaxle can be removed and serviced independently of other components.
TOOLS Miscellaneous R E QUIRED TOOL S 2 Screw Drivers 3/8” Drive Ratchet Rubber Mallet Large External Retaining Ring Pliers Large Internal Retaining Ring Pliers Small External Retaining Ring Pliers Small Internal Retaining Ring Pliers AN-04 (1/8 Allen) AN-06 (3/16 Allen) AN-08 (1/4 Allen) AN-10 (5/16 Allen) AN-12 (3/8 Allen) T-25 Torx T-40 Torx 3 Jaw Puller TORQUES 33 mm socket 1/2” socket 3/4” socket 9/16” socket 7/8” socket 13/16” socket 15/16” socket 1 1/8” socket 1 7/16” socket Sockets As a genera
TRANSAXLE REMOVAL NOTE: It is necessary to remove the ZT-5400 Powertrain® from the vehicle before performing the repair procedures presented in this section. Before starting any disassembly, make certain that your work area is neat and clean. Clean the external parts of the transaxle. The following procedures are presented in the order recommended for a complete tear down of the transaxle. Do not disassemble the unit any farther than necessary to accomplish the required repairs.
FAN AND PULLEY AXLE HUB ASSEMBLY Refer to Figure 8 Refer to Figure 8 1. Remove the locknut (183) and the washer (182). 1. Remove the axle cap and discard (114). 2. Remove the cotter pin and discard (116). 2. Remove the fan (181) and the washer (184). 3. Remove the castle nut (113). 3. Remove the pulley assembly (180). 4. Remove the taper hub assembly (111) and discard. Assembly NOTE: A new hub will have to be ordered to replace the discarded hub. 1.
RETURN TO NEUTRAL ASSEMBLY OPTION Refer to Figure 9 Disassembly Assembly 1. Remove all items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the spring (64). 2. When tightening the fasteners, refer to the table on page 15 for the required torque values. 3. Remove the Torx head screw (56) and discard. Remove the washer (63). 4. Remove the scissor arm (62).
CONTROL ARM ASSEMBLY Refer to Figure 10 Disassembly Assembly 1. Remove all items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the Torx head screw (56) and discard. 2. When tightening the fasteners, refer to the table on page 15 for the required torque values. 3. Remove the nut (57) and the washer (55). 4. Remove the control arm (54). 5. Remove the plastic washer (53) and the stud (52). 6. Remove the stop plate (65).
FILTER AND FILTER COVER Refer to Figure 11 Disassembly Assembly 1. Remove the filter cover (152). 1. Install the new filter (150). 2. Remove the O-ring (151) from the cover (152) and discard. 2. Install the new O-ring (151) onto the cover (152). 3. Remove the filter (150) and discard. 3. Install the filter cover (152). Refer to torque chart on page 15. Inspection 1. Inspect all parts for wear or damage. Replace as necessary. 2. Check for old filter grommet stuck on the filter tube.
BRAKE ASSEMBLY Refer to Figure 12 Disassembly Assembly 1. Remove all items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Mark the orientation of the brake arm (130) before removal. 2. Install new seal (127) from seal kit. 3. Remove the retaining ring (131) and discard. 4. Remove the brake handle (130) and the bushing (128). 5. Remove the seal (127) and discard.
2–SPEED ARM (OPTIONAL) Refer to Figure 13 Disassembly Inspection 1. Remove all external items previously discussed in their recommended order. 1. Inspect the 2–speed actuating handle (168) and the 2–speed lock-down arm (165) for excessive wear or damage. Replace if necessary. 2. Remove the external retaining ring (169) and discard. Remove the 2-speed arm (168). NOTE: Only remove the 2-speed lock-down arm (165) if damaged. Mark the orientation before removal. 3.
BYPASS ACTUATOR Refer to Figure 14 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the retaining ring (45), wave spring (44) and discard; then, remove the bypass actuator rod (43). 2. Install a new lip seal (41). 3. Remove the lip seal (41) and discard. NOTE: Only remove the seal (41) if damaged or worn, or if doing a complete disassembly. 3.
SIDE HOUSING Refer to Figure 15 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the retaining ring (107), the seal (106) and discard. 2. Apply a bead of sealant around the perimeter of the main housing face. See “Sealant Application Diagram” on page 34. 3. Remove the screws (6), then separate side housing (2) from main housing (1). Inspection 3.
AXLE SHAFT AND PLANETARY GEAR SET Refer to Figure 16, 17 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. NOTE: Note the location of the ring gear tabs. 1 2. Remove the axle shaft (103) and the planetary assembly. RING GEAR TAB PLANETARY ASSEMBLY 3. Remove the axle bearing (105) and washer (104). 4. Remove the axle shaft thrust ball (100) from the main house (1). 103 5.
CHARGE PUMP AND OIL TUBE Refer to Figure 18 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Pry out the oil tube (38). 3. Mark the orientation of the charge pump cover (144). 2. When installing the charge pump cover (144) line up the mark on the cover with the mark on the housing — refer to Disassembly step 3. 4.
INPUT SHAFT Refer to Figure 19 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the retaining ring (75) and discard. 2. Install the input shaft assembly into the main housing. 3. Remove the lip seal (74) and discard. 3. Install the washer (73). 4. Remove the washer (73). 4. Install the new lip seal (74) and new retaining ring (75). 5.
SWASHPLATE Refer to Figure 20, 21 Disassembly 4. Inspect the pump cylinder block (88). 1. Remove all external items previously discussed in their recommended order. Assembly 2. Remove the trunnion arm (50), swashplate, the thrust bearing (85) and the pump block assembly. Inspection 1. Inspect the races of the thrust bearing (85) for wear or damage. 2. Inspect the pistons (86) and washers (82) of the pump block assembly for scratches and or wear. Replace the pump block assembly if necessary. 3.
CENTER SECTION Refer to Figure 22 Disassembly Assembly 1. Remove all external items previously discussed in their recommended order. 1. Reassemble all parts in the reverse order of disassembly. 2. Remove the grommet (37) from the center section assembly. 2. Apply a light coating of oil to all running surfaces. 3. Remove the center section bolts (21) and (22). 3. When tightening the fasteners, refer to the table on page 15 for the required torque values. 4.
BRAKE ASSEMBLY AND MOTOR SHAFT Refer to Figure 23 Disassembly Inspection 1. Remove all external items previously discussed in their recommended order. 1. Inspect for scratches and or damage to the brake rotor (123). NOTE: If the brake is working properly and the brake components are not damaged, there is no need to remove the brake assembly. 2. Inspect the puck (124) for excessive wear. 2. Pull the motor shaft (90), retaining ring (192) and gear (93) out of the center section (20). Assembly 3.
MOTOR CYLINDER BLOCK, OPTIONAL 2-SPEED SHAFT & SWASHPLATE Refer to Figure 24 Disassembly Inspection 1. Remove all external items previously discussed in their recommended order. 1. Inspect the races of the thrust bearing (80) for wear or damage. 2. Disassemble the motor block assembly and inspect all parts. 2. Inspect the pistons (81), washers (82) and the motor cylinder block (84) of the motor block assembly for scratches and or wear. Replace the motor block assembly if necessary. 3.
CENTER SECTION AND MAGNET Refer to Figure 25 Disassembly Assembly 1. Remove all items previously discussed, in their recommended order. 1. Assemble items in reverse order of disassembly. 2. Pry off the charge galley cap (25). 2. When tightening components refer to the table on page 15 for the required torque values. NOTE: Mark orientation of the shock valves before removing. 3. Remove the shock valve seats (26). 4.
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 36. 1.
ASSEMBLY AFTER A COMPLETE TEARDOWN (CONTINUED) socket head capscrew (61). Place the control arm (54) on the trunnion shaft. Install the RTN assembly (62), washer (63) onto the trunnion shaft and secure with Torx head capscrew (56). Install the spring (64) on the RTN assembly. 19. Install the axle seal (106) and retaining ring (107) into the side cover (2). Place the axle shaft key (110) into the keyway on the axle. Slide the hub (111) onto the axle and secure with the castle nut (113).
SIDE HOUSING – SCREW TIGHTENING SEQUENCE Starting with the number “1” screw location, tighten sequentially through to “17.” Torque each screw to 230 – 290 lb-in (25.9 – 32.7 Nm). NOTE: As a general rule, use the low end of the torque specification.
CASTLE NUT (113) ALTERNATE TORQUE METHOD NOTE: The ideal method for installing a new hub and nut is utilizing a torque wrench capable of 275 ft-lbs. If a 275 ft-lbs torque wrench is not available please use the alternative procedure outlined in this document. All parts need to be clean and free of lubrication. Tools: Procedure: 1. 1. 2. 3. 4. 5. 2. 3. 4. 5. 6.
ZT-5400 Powertrain 37
45 44 43 41 181 ZT-5400 POWERTRAIN® EXPLODED VIEW 38 ZT-5400 Powertrain
ZT-5400 POWERTRAIN® TRANSAXLE PARTS LIST 1 2 5 6 11 20 21 22 25 28 34 35 36 37 38 40 41 43 44 45 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 70 73 74 75 80 84 85 88 90 91 92 93 94 95 96 97 98 100 101 102 Housing, Main Housing, Side Dowel Pin Screw, HWHST 5/16-18 X 1.5 Bearing, Needle 1.125 X 1.375 X 1.000 Center Section Bolt, Center Section, Long Bolt, Center Section Check Plug/w Assembly Shock Valve Ball, .375 Plastic Spring, Compression .375 X .75 LSHCS, 5/8-11X.
GLOSSARY OF TERMS Axial Piston: Type of design for hydraulic motors and pumps in which the pistons are arranged parallel with the spindle (input or output shaft). Bypass Valve: A valve whose primary function is to open a path for the fluid to bypass the motor or pump. Also referred to occasionally as the freewheel valve or dump valve. Case Drain Line (Return Line): A line returning fluid from the component housing to the reservoir.
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.
NOTES 42 ZT-5400 Powertrain
NOTES ZT-5400 Powertrain 43
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