Toro 72043, 72046, 72048, 72063, 72064 Service Manual

...

TUFF-TORQ K61A TRANSAXLE SERVICE MANUAL

Table of Contents – Page 1 of 2

SAFETY INFORMATION

SPECIFICATIONS

REMOVING THE TRANSAXLE FROM THE TRACTOR

TRANSAXLE DISASSEMBLY AND INSPECTION PINION DIFFERENTIAL GEAR CENTER CASE MOTOR SHAFT PUMP SHAFT

TRANSAXLE ASSEMBLY AND ADJUSTMENT BYPASS RETURN BRAKE INTERLOCK NEUTRAL ADJUST ECCENTRIC PUMP SHAFT SWASH PLATE PUMP CYLINDER BLOCK MOTOR SHAFT CENTER CASE MOTOR SHAFT AND CENTER CASE INSTALLATION DIFFERENTIAL GEAR AXLE SHAFTS AND DIFFERENTIAL INSTALLATION PINION TRANSAXLE CASE BRAKE DAMPER BLEEDING AIR FROM THE OIL CIRCUIT UNIT OUT OF TRACTOR UNIT IN TRACTOR TRANSAXLE NEUTRAL ADJUSTMENT

BELTS AND LINKAGE BELT REPLACEMENT BELT ROUTING - BOTTOM VIEW REASSEMBLY BELT ADJUSTMENT BRAKE LINKAGE FOOT BRAKE DESCRIPTION AND OPERATION ADJUSTMENT PARKING BRAKE DESCRIPTION AND OPERATION TRANSAXLE BRAKE DESCRIPTION AND OPERATION BRAKE BAND ADJUSTMENT

TUFF-TORQ K61A TRANSAXLE SERVICE MANUAL

Table of Contents – Page 2 of 2

BELTS AND LINKAGE -Continued

HYDROSTATIC CONTROL LINKAGE DESCRIPTION AND OPERATION LUBRICATION PEDAL ADJUSTMENT CRUISE CONTROL DESCRIPTION AND OPERATION COMPONENTS PLATE-HYDROSTATIC CONTROL ARM AND HOUSING BRACKET MAGNET MAGNET BRAKE SWITCH AND MOUNTING BRACKET RELAY

TROUBLESHOOTING

Tuff-Torq

K61A Transaxle

About This Manual

This manual was written expressly for servicing Tuff Torq K61A transaxles, as used in 1994--1999 260-Series Toro Wheel Horse tractors. The Toro Company has made every effort to make the information in this manual complete and correct.

This manual was written for the service technician; basic mechanical/electrical skills are assumed. The Contents page lists the systems and the related topics covered in this manual.

We hope that you will find this manual a valuable addition to your service shop. If you have any questions or comments regarding this manual, please contact us at the following address:

The Toro Company Consumer Service Department 8111 Lyndale Avenue South Bloomington, MN 55420--1196

Portions of this manual are reprinted courtesy of Tuff Torq Corporation and New Holland North America.

The Toro Company reserves the right to change product specifications or this manual without notice.

The Toro Company – 2000

Bloomington, MN 55420 – U.S.A

Contents

Safety Information 3.............................

Specifications 4.................................

Removing the Transaxle from the Tractor 5........

Transaxle Disassembly and Inspection 6..........

Pinion 14..........................................

Differential Gear 14.................................

Center Case 15....................................

Motor Shaft 15.....................................

Pump Shaft 16.....................................

Transaxle Assembly and Adjustment 17............

Bypass Return 17..................................

Brake Interlock 17..................................

Neutral Adjust Eccentric 19..........................

Pump Shaft 20.....................................

Swash Plate 20....................................

Pump Cylinder Block 21.............................

Motor Shaft 22.....................................

Center Case 23....................................

Motor Shaft and Center Case Installation 23...........

Differential Gear 25.................................

Axle Shafts and Differential Installation 25.............

Pinion 26..........................................

Transaxle Case 27.................................

Brake 28..........................................

Damper 29........................................

Bleeding Air from the Oil Circuit 29...................

Unit Out of Tractor 29..........................

Unit in Tractor 29..............................

Transaxle Neutral Adjustment 30.....................

Belts and Linkage 31..............................

Belt Replacement 31...............................

Belt Routing—Bottom View 32.......................

Reassembly 32....................................

Belt Adjustment 33.................................

Brake Linkage 35..................................

Foot Brake 35.................................

Description and Operation 35...............

Adjustment 35............................

Parking Brake 35..............................

Description and Operation 35...............

Transaxle Brake 36.................................

Description and Operation 36....................

Brake Band Adjustment 37..........................

Hydrostatic Control Linkage 38.......................

Description and Operation 38....................

Lubrication 38.................................

Pedal Adjustment 38...............................

Cruise Control 39..................................

Description and Operation 39....................

Components 39...............................

Plate-Hydrostatic Control Arm and Housing 39.....

Bracket Magnet 40.............................

Magnet 40....................................

Brake Switch and Mounting Bracket 40...........

Relay 40......................................

Troubleshooting 41...............................

2 Tuff Torq Model K61A Hydrostatic TransaxleContents

Safety Information

This symbol means WARNING or PERSONAL SAFETY INSTRUCTION— read the instruction because it has to do with your safety. Failure to comply with the instruction may result in personal injury or even death.

This manual is intended as a service and repair manual only. The safety instructions provided herein are for troubleshooting, service, and repair of the Tuff Torq

Think Safety First

Avoid unexpected starting of engine...

Always turn off the engine and disconnect the spark plug wire(s) before c leaning, adjusting, or repair.

Avoid injury from high pressure oil...

Keep body and hands away from pin hole leaks or nozzles that eject high pressure oil. Use cardboard or paper to locate hydraulic leaks. Oil escaping under high pressure can penetrate the skin and cause injury. Oil accidentally injected into the skin must be surgically removed within a few hours by a doctor familiar with this form of injury or gangrene may result.

Avoid laceration and amputations...

model K61A hydrostatic transaxle. The tractor and attachment operator’s manuals c ontain safety information and operating tips for safe operating practices. Operator’s manuals are available through your local Toro distributor or:

The Toro Company Publications Department 8111 Lyndale Avenue South Bloomington, MN 55420--1196

Avoid asphyxiation...

Never operate an engine in a confined area without proper ventilation.

Avoid injury from batteries...

Battery acid is poisonous and can cause burns. Avoid contact with skin, eyes, and clothing. Battery gases can explode. Keep cigarettes, sparks, and flames away from the battery.

Avoid injury due to inferior parts...

Use only original equipment parts to ensure that important safety criteria are met.

Stay clear of all moving parts whenever the engine is running. Treat all normally moving parts as if they were moving whenever the engine is running or has the potential to start.

Avoid burns...

Do not touch the engine, muffler, or other components which may increase in temperature during operation, while the unit is running or shortly after it has been running.

Avoid fires and explosions...

Avoid spilling fuel and never smoke while working with any type of fuel or lubricant. Wipe up any spilled fuel or oil immediately. Never remove the fuel cap or add fuel when the engine is running. Always use approved, labeled containers for storing or transporting fuel and lubricants.

Avoid injury to bystanders...

Always clear the area of bystanders before starting or testing powered equipment.

Avoid injury due to projectiles...

Always clear the area of sticks, rocks, or any other debris that could be picked up and thrown by the powered equipment.

Avoid modifications...

Never alter or modify any part unless it is a factory approved procedure.

Avoid unsafe operation...

Always test the safety interlock system after making adjustments or repairs on the machine.

3Tuff Torq Model K61A Hydrostatic Transaxle Safety Information

Specifications

Axle Torque Output

Rated: 215 ft. lb. (290 NSm)........................

Peak:

Maximum Input Speed 3000 RPM.............

Input Shaft Size 0.58 in. (14.85mm)...................

.........................

654 ft. lb. (880 NSm)

Reduction Ratio

Axle Shaft Size 1.0 in. (25.4mm)....................

Maximum Static Weight on Axle 584 lb. (265kg)....

Weight — Dry

Brake

Brake Capacity 288 ft. lb. (390 NSm) at 55 lb. (245NSm) Brake Arm Force....................

Differential

Gears Heat-Treated............................

Housings Aluminum Die Castings.........................

Tow Valve

Oil

Oil Capacity

Ground Speed

.............................

...............................

Maximum Forward 5.3 MPH (8.5km/hr).............

Maximum Reverse 2.3 MPH (3.7km/hr).............

...................

.....................

........................

......................

26.97:1

38 lb. (17.5kg)

Dry Band

Automotive-Type Bevel Gears

Standard (Brake Release)

10W--30 API Service Class H or Higher

3.5 qt. (3.3 liter)

4 Tuff Torq Model K61A Hydrostatic TransaxleSpecifications

Removing the

Disconnect the brake rod, control rod, tow valve rod, and reservoir hose from the top of the transaxle.

Transaxle from the Tractor

Working from the bottom of the tractor, remove the transaxle drive belt tension spring and drive belt from the transaxle pulley.

Remove the access panel from the rear of the tractor, to expose the fuel tank/transaxle.

Support the rear of the tractor with jack stands and remove the rear wheels.

Remove the two bolts securing the transaxle support rods to the tractor frame.

Remove the four nuts from the U-bolts which hold the two axle shafts to the frame.

Remove the transaxle and place it upright on the work bench.

Remove the fan and spacer from the input pulley (three cap screws).

Remove the pulley from the shaft (one snap ring).

Figure 1

Figure 2

5Tuff Torq Model K61A Hydrostatic Transaxle Removing the Transaxle from the Tractor

Transaxle Disassembly and Inspection

Begin disassembly and inspection of the transaxle by thoroughly cleaning the outside surface of the transmission.

IMPORTANT: Clean your work area thoroughly and cover the workbench with clean paper. This is extremely important as just one grain of sand can cause a hydrostatic transmission to fail.

Remove the drain bolt from the bottom center and drain the oil from the transaxle sump.

Remove the shock absorber by detaching the E clip, washer, and cotter pin and its washer. Later models use a spring clip retainer to secure the shock absorber.

Figure 5

Figure 6

Remove the band brake assembly and brake rod component by taking out the cotter pin, washer, and three 12mm bolts. Replace the assembly if the friction material or actuating parts are worn or damaged.

Figure 3

Remove the pressure fill plug and drain the oil from the rotating groups.

Figure 4

Remove the ring and brake drum.

IMPORTANT: The brake drum and brake band must be free from oil or dust.

Figure 7

6 Tuff Torq Model K61A Hydrostatic TransaxleTransaxle Disassembly and Inspection

Open the transaxle case by taking out the 13 perimeter 12mm bolts and the single center bolt. Pry the bottom half of the case free from the top half, using care not to damage the seating surface.

Remove the differential gear assembly.

Figure 11

Figure 8

Lift the pinion shaft assembly from the upper case. There is a ball bearing on one end of the shaft and a bushing on the other end.

Figure 9

Remove the collar and ring from the left and right axle shaft.

Remove the left and right axle shaft and two bushings from the upper case.

Figure 12

Remove the two seals from the upper case. Remove the axle bearings if replacing.

Inspect all parts for wear or damage and replace if necessary.

Figure 10

Figure 13

7Tuff Torq Model K61A Hydrostatic Transaxle Transaxle Disassembly and Inspection

Measure the inside diameter of the bushings and the outside diameter of the left and right axle shaft.

Tab le 1

Measurement Should be:

Disconnect the C arm from the push valve bypass shaft.

Remove the two push pins, springs, and valves from the center case.

Bushings -

Inside Diameter

Axle Shaft

Outside Diameter

22.06-22.15mm (.868-.872″)

21.98-22mm (.865-.866″)

Clearance 0.08-0.17mm

(.003-.006″)

Maximum Wear Limit 0.5mm (.019″)

Measure the inside diameter of the axle bores in the housing and the outside diameter of the left and right axle shaft.

Tab le 2

Measurement

Housing Axle Bore --

Inside Diameter

Axle Shaft

Outside Diameter

Should be:

25.44-25.53mm (1.001-1.005″)

25.32-25.38mm

(.996-.999″)

Clearance 0.06-0.21mm

(.002-.008″)

Figure 15

Remove sleeve A1, sleeve A2, the two backup rings, packings, balls, ball holders, springs, and bypass holders, using air pressure if necessary.

Note: Remove the two check valve assemblies only if necessary (leaking, sticking, or if extra-thorough cleaning is necessary). Air pressurization will remove one valve; the other can be pushed out from behind, after the center section is removed.

Maximum Wear Limit 0.5mm (.019″)

Take the filter out of the center case.

Replace the filter whenever transaxle is

Note:

disassembled for service.

Figure 14

1. Valve A1

2. Valve A2

Figure 16

3. Pressurize with air to remove valves, if needed (pressure fill plug shown installed, with allen head plug removed).

8 Tuff Torq Model K61A Hydrostatic TransaxleTransaxle Disassembly and Inspection

Carefully inspect the packings (o-rings) to ensure they are not deformed, cut, or scratched. Use new packings on reassembly.

IMPORTANT: When removing the sleeves, note that their valves are different, and therefore not interchangeable. The A1 valve, located farthest from the axle, has a small hole in it, in addition to the large hole in the center. For reassembly purposes, mark the port from which this valve is removed.

Remove the cylinder block from the pump shaft.

IMPORTANT: Be sure the pistons do not fall out of the block during removal.

Figure 17

1. Note hole

Loosen the three bolts and remove the magnet from the center case. Clean the magnet thoroughly; use air pressure if necessary.

Figure 18

Make a mark on the top of the motor thrust bearing housing, for easy identification during reassembly.

Remove the motor shaft assembly, along with the center case assembly, from the upper case.

IMPORTANT: Pay close attention to t he contact surfaces of the center case and cylinder blocks to prevent damage.

Figure 20

Inspect the five cylinder bores for burrs or scoring. The cylinder block and center section must be replaced if any scratch is deep enough to catch on a fingernail.

Figure 21

Inspect the five pistons and all parts of the cylinder block assembly for wear or damage.

Replace the center case and both cylinder block assemblies if any cylinder block assembly parts are damaged.

Figure 19

Figure 22

9Tuff Torq Model K61A Hydrostatic Transaxle Transaxle Disassembly and Inspection

Measure the clearance between the swash plate and shift blocks.

Replace both shift blocks and the swash plate with new parts if they are beyond the maximum wear limit.

Tab le 3

Inspect the swash plate, thrust bearing, thrust plates, and bushing for w ear or damage. Replace with new parts if necessary.

Measurement

Should be:

Clearance 0.01-0.11mm

(.0003-.004″)

Maximum Wear Limit 0.15mm (.005″)

Remove the spring and ring from the pump s haft.

Figure 25

Figure 23

Remove the swash plate subassembly from the pump shaft.

Figure 24

Figure 26

Figure 27

10 Tuff Torq Model K61A Hydrostatic TransaxleTransaxle Disassembly and Inspection

Remove the shift blocks from the control shaft and inspect them for wear or damage. Replace if necessary.

Remove the input shaft, seal, and bearing from the upper case. Remove oil seal and large snap ring from the upper case. Remove the input shaft and bearing from the case.

Figure 28

Figure 29

Remove the two metal thrust pads from the upper case and inspect them for wear or damage.

Replace both thrust pads with new parts if the maximum wear limit is exceeded.

Tab le 4

Figure 30

Figure 31

Measurement

Should be:

Thickness 1.45-1.55mm

(.057-0.61″)

Maximum Wear Limit 1.30mm (.051″)

Figure 32

11Tuff Torq Model K61A Hydrostatic Transaxle Transaxle Disassembly and Inspection

Note: If servicing a transaxle with low to moderate use, it

is not necessary to disassemble or remove any of the levers or linkages from the upper case, unless a part is damaged or there is an oil leak. If doing a complete rebuild, all shafts should be removed, inspected, and packings (o-rings) replaced. If leaving the shafts in place, avoid excessive use of cleaning solvent on the upper case half, and do not use solvent that will damage the packings.

Detach the torsion spring from the control shaft.

Figure 33

Inspect the control shaft, fulcrum, and torsion spring for wear or damage and replace if necessary.

Figure 36

Inspect the packings (o-rings) to ensure that they are not cut, scratched, or deformed.

Remove the roll pin and lever from the control shaft subassembly and the lock nut from the neutral adjusting fulcrum.

Figure 34

Figure 37

Drive the roll pin from the brake arm secured to the internal brake shaft.

Remove the brake arm from the brake shaft.

Figure 35

Figure 38

12 Tuff Torq Model K61A Hydrostatic TransaxleTransaxle Disassembly and Inspection

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