The KUBOTA STA-30, STA-35 TRACTOR Repair Service Manual we provide is a Complete Informational book in an all-device compatible PDF Format. This service manual has easy-to-read and apply section-wise instructions to repair every part from headlight to rear lights, and from top to bottom. The KUBOTA STA-30, STA-35 TRACTOR Service Repair Manual has technical erudition regarding the KUBOTA STA-30, STA-35 TRACTOR. The manual contains simple conversion of complex fixation techniques applied by repairmen at workshops.

1. Kubota Sta30
2. Kubota Sta 30 Manual

. WORKSHOP MANUAL TRACTOR ST -30,ST -35 KiSC issued 11, 2006 A.

TO THE READER This Workshop Manual has been prepared to provide servicing personnel with information on the mechanism, service and maintenance of KUBOTA Tractor STα-30 and STα-35. It is divided into two parts, “Mechanism” and “Servicing” for each section. Mechanism Information on the construction and function are included. STα-30 STα-35, WSM SAFETY INSTRUCTIONS SAFETY INSTRUCTIONS SAFETY FIRST This symbol, the industry’s “Safety Alert Symbol”, is used throughout this manual and decals on the machine itself to warn of the possibility of personal injury.

Read these instructions carefully. It is essential that you read the instructions and safety regulations before you attempt to repair or use this unit. STα-30 STα-35, WSM SAFETY INSTRUCTIONS SAFETY STARTING. Do not start the engine by shorting across starter terminals or bypassing the safety start switch. Do not alter or remove any part of machine safety system.

Before starting the engine, make sure that all shift levers are in neutral positions or in disengaged positions. STα-30 STα-35, WSM SAFETY INSTRUCTIONS VENTILATE WORK AREA. If the engine must be running to do some work, make sure the area is well ventilated.

Never run the engine in a closed area. The exhaust gas contains poisonous carbon monoxide.

PREVENT ACID BURNS. STα-30 STα-35, WSM SAFETY INSTRUCTIONS SAFETY DECALS The following safety decals are installed on the machine. If a decal becomes damaged, illegible or is not on the machine, replace it. The decal part number is listed in the parts list. KiSC issued 11, 2006 A.

STα-30 STα-35, WSM SAFETY INSTRUCTIONS KiSC issued 11, 2006 A. STα-30 STα-35, WSM SAFETY INSTRUCTIONS KiSC issued 11, 2006 A. SPECIFICATIONS Model STα-30 STα-35 PTO power 17.3 kW (23.5 PS) 21.0 kW (28.5 PS) Maker KUBOTA Model D1463-M-ST D1703-M-ST Type ETVCS, Indirect Injection. Vertical, water-cooled, 4-cycle diesel Number of cylinders 82 × 92.4 mm (3.23 × 3.64 in.) 87 × 92.4 mm (3.43 × 3.64 in.). Revolution 540 / 2673 min (rpm), 800 / 2738 min (rpm) PTO system PTO shaft USA No. 5 (KUBOTA 10-tooth) involute spline Mid. Revolution 1700 / 2710 min (rpm), 2500 / 2755 min (rpm) Note:.

Manufacture’s estimate the company reserves the right to change the specifications without notice. STα-30 STα-35, WSM TRAVELLING SPEED TRAVELLING SPEED Model STα-30 STα-35 Tire size (Rear) 9.5-22 12.4-16 13.6-16 Range gear shift lever km/h (mile/h) km/h (mile/h) km/h (mile/h) 1 (Low) 0 to 6.6 (0 to 4.1) 0 to 6.3 (0 to 3.9) 0 to 6.5 (0 to 4.0) 2 (Middle) 0 to 12.7 (0 to 7.9). STα-30 STα-35, WSM DIMENSIONS DIMENSIONS KiSC issued 11, 2006 A.

GENERAL KiSC issued 11, 2006 A. GENERAL CONTENTS 1.

TRACTOR IDENTIFICATION. GENERAL PRECAUTIONS.G-3 4. HANDLING PRECAUTIONS FOR ELECTRICAL PARTS AND WIRING.

G-4 1 WIRING. G-4 2 BATTERY.G-6 3 FUSE.G-6 4 CONNECTOR. G-6 5 HANDLING OF CIRCUIT TESTER.G-7 5. STα-30 STα-35, WSM G GENERAL 1.

Hydraulic Power Steering 2. E-TVCS (Three Vortex Combustion System) Diesel Engine 3. Engine Key Shut-Off System 4. Hydrostatic Transmission (HST) 5.

3 Range of Speed 6. Bi-speed Turn 7. Cruise Control 8.

STα-30 STα-35, WSM G GENERAL 2. TRACTOR IDENTIFICATION When contacting your local KUBOTA distributor, always specify engine serial number, tractor serial number and hour meter reading. (1) Tractor Identification Plate (3) Engine Serial Number (2) Tractor Serial Number (4) Hour Meter. Screws, bolts and nuts should be installed in their original position to prevent reassembly errors. When special tools are required, use KUBOTA genuine special tools.

Special tools which are not frequently used should be made according to the drawings provided. STα-30 STα-35, WSM G GENERAL 4. HANDLING PRECAUTIONS FOR ELECTRICAL PARTS AND WIRING To ensure safety and prevent damage to the machine and surrounding equipment, heed the following precautions in handling electrical parts and wiring.

IMPORTANT. Check electrical wiring damage loosened. STα-30 STα-35, WSM G GENERAL. Securely clamp, being careful not to damage wiring.

(1) Clamp (3) Clamp. Wind Clamp Spirally (4) Welding Dent (2) Wire Harness W1011458. Clamp wiring so that there is no twist, unnecessary sag, or excessive tension, except for movable part, where sag be required. STα-30 STα-35, WSM G GENERAL 2 BATTERY.

Take care not to confuse positive and negative terminal posts. When removing battery cables, disconnect negative cable first. When installing battery cables, check for polarity and connect positive cable first. STα-30 STα-35, WSM G GENERAL. Use sandpaper to remove rust from terminals. Repair deformed terminal. Make certain there is no terminal being exposed or displaced.

(1) Exposed Terminal (3) Sandpaper (2) Deformed Terminal (4) Rust W1012346. Make certain that there is no female connector being too open. (A) Correct (B) Incorrect W1012430. Above 25 °C (77 °F): SAE30, 10W-30 or 10W-40 18.5 L Transmission case 4.89 U.S.gals. KUBOTA SUPER UDT fluid.

4.07 Imp.gals. 4.0 L KUBOTA SUPER UDT fluid. or SAE80, 90 gear Front axle case 1.06 U.S.gals. 0.88 Imp.gals.

Grease Place No. Of greasing point Capacity. STα-30 STα-35, WSM G GENERAL 6.

TIGHTENING TORQUES Screws, bolts and nuts whose tightening torques are not specified in this Workshop Manual should be tightened according to the table below. 1 GENERAL USE SCREWS, BOLTS AND NUTS Indication on top of No-grade or 4T bolt SCr435. STα-30 STα-35, WSM G GENERAL 7.

MAINTENANCE Service Time Interval Period Reference Important Item 2 years page Engine oil Change G-12 Engine oil filter Replace G-12 Transmission fluid Change G-13 Hydraulic oil filter (for HST) Replace G-13 Hydraulic oil filter Replace G-13 Front axle case oil. STα-30 STα-35, WSM G GENERAL 8.

CHECK AND MAINTENANCE CAUTION. Be sure to check and service the tractor on a flat place with engine shut off, the parking brake on and chock the wheels. 1 DAILY CHECK To prevent trouble from occurring, it is important to know the condition of the tractor. Check the following items before starting. Then, replenish the engine oil up to the specified level. IMPORTANT.

To prevent serious damage to the engine, replacement element must be highly efficient. Use only a KUBOTA genuine filter or its equivalent. (1) Engine Oil Filter W1014892.

Check the fluid level. IMPORTANT. To prevent serious damage to the hydraulic system. Use only a genuine KUBOTA filter or its equivalents.

(1) Drain Plug (3) Hydraulic Oil Filter (for HST) (2) Hydraulic Oil Filter. After draining, screw in the two drain plugs. Fill new oil from filling port with specified amount of oil. IMPORTANT. Use KUBOTA SUPER UDT fluid or SAE 80, 90 gear oil. Refer to “LUBRICANTS, FUEL AND COOLANT”.

(See page G-8.) 4.0 L. STα-30 STα-35, WSM G GENERAL 3 CHECK POINTS OF EVERY 50 HOURS Greasing 1.

Apply a grease to the following position as figures. (1) Grease Fitting (Top Link) (4) Grease Fitting (Brake Pedal Shaft) (2) Grease Fitting (Lifting Rod RH) (5) Grease Fitting (Clutch Pedal Shaft) (3) Battery Terminal W1016347. STα-30 STα-35, WSM G GENERAL Checking Engine Start System CAUTION. Do not allow anyone near the tractor while testing. If the tractor does not pass the test do not operate the tractor. Preparation before testing. Sit on operator’s seat.

STα-30 STα-35, WSM G GENERAL 4 CHECK POINTS OF EVERY 100 HOURS Changing Engine Oil 1. See page G-12. W1017133 Checking Clutch Pedal Free Travel 1. See page G-14. W1017188 Cleaning Air Cleaner Element Single Element and Double Element Type 1. STα-30 STα-35, WSM G GENERAL Cleaning Fuel Filter This job should not be done in the field, but in a clean place. Close the fuel filter cock (1).

Unscrew the screw ring and remove the fuel filter bowl (2), and rinse the inside with kerosene. STα-30 STα-35, WSM G GENERAL Checking Fan Belt Tension CAUTION. Be sure to stop engine before checking belt tension.

Stop the engine and remove the key. Apply moderate thumb pressure to belt between pulleys.

If tension is incorrect, loosen the alternator mounting bolts and using a lever placed between the alternator and the engine block, pull the alternator out until the deflection of the belt falls within acceptable limits. STα-30 STα-35, WSM G GENERAL Checking Parking Brake CAUTION. Be sure to stop engine before checking parking brake. Slowly raise the parking brake lever (1) to the ratchet sound made by the parking brake lever. Of notch is not within the factory specifications, loosen the lock nut (2) and turn the brake rod LH (3) and RH (4) to adjust within acceptable limits.

STα-30 STα-35, WSM G GENERAL Checking Battery Condition DANGER To avoid the possibility of battery explosion: For the refillable type battery, follow the instructions below. Do not use or charge the refillable type battery if the fluid level is below the LOWER (lower limit level) mark. STα-30 STα-35, WSM G GENERAL Battery Charging CAUTION. When the battery is being activated, hydrogen and oxygen gases in the battery are extremely explosive.

Keep open sparks and flames away from the battery at all times, especially when charging the battery. STα-30 STα-35, WSM G GENERAL Checking Radiator Hose and Hose Clamp Check to see if radiator hoses are properly fixed every 200 hours of operation or six months, whichever comes first. If hose clamps are loose or water leaks, tighten bands securely. STα-30 STα-35, WSM G GENERAL Adjusting Toe-in 1. Park the tractor on the flat place.

Inflate the tires to the specified pressure. Turn steering wheel so front wheels are in the straight ahead position. Lower the implement, lock the parking brake and stop the engine. STα-30 STα-35, WSM G GENERAL 8 CHECK POINTS OF EVERY 800 HOURS Checking Valve Clearance 1. See page 1-S21.

W1021033 9 CHECK POINTS OF EVERY 1 YEAR Replacing Air Cleaner Element (Primary) and Secondary Element 1. See page G-17. W1021125 10 CHECK POINTS OF EVERY 2 YEARS Replacing Radiator Hose (Water Pipes). STα-30 STα-35, WSM G GENERAL Flushing Cooling System and Changing Coolant CAUTION.

Do not remove the radiator cap when the engine is hot. Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely.

STα-30 STα-35, WSM G GENERAL Flashing Cooling system and Changing Coolant (Continued) Anti-Freeze If coolant freezes, it can damage the cylinders and radiator. It is necessary, if the ambient temperature falls below 0 °C (32 °F), to remove coolant after operating or to add anti-freeze to it. STα-30 STα-35, WSM G GENERAL 11 OTHERS Bleeding Fuel System Air must removed: 1. When the fuel filter or lines are removed. When tank is completely empty. After the tractor has not been used for a long period of time.

Bleeding procedure is as follows: 1. Refer to troubleshooting section of this manual or your local KUBOTA distributor for specific information dealing with electrical problems. If any of them should blow, replace with a new one of the same capacity. STα-30 STα-35, WSM G GENERAL 9. SPECIAL TOOLS 1 SPECIAL TOOLS FOR ENGINE Special Use Puller Set Code No: 2 Application: Use exclusively for pulling out bearing, gears and other parts with ease. W1024050 Piston Ring Compressor Code No: 1 Application: Use exclusively for pushing in the piston with piston rings into the cylinder.

STα-30 STα-35, WSM G GENERAL Oil Pressure Tester Code No: 2 Application: Use to measure lubricating oil pressure. (1) Gauge (5) Adaptor 2 (2) Cable (6) Adaptor 3 (3) Threaded Joint (7) Adaptor 4 (4) Adaptor 1 (8) Adaptor 5 W1024318 Valve Seat Cutter Code No. STα-30 STα-35, WSM G GENERAL Auxiliary Socket For Fixing Crankshaft Sleeve Code No: 1 Application: Use to fix the crankshaft sleeve of the diesel engine.

W1077114 Plastigage Code No: 1 Application: Use to check the oil clearance between crankshaft and bearing, etc. STα-30 STα-35, WSM G GENERAL NOTE. The following special tools are not provided, so make them referring to the figure. Valve Guide Replacing Tool Application: Use to press out and press fit the valve guide. Dia.) 11.7 to 11.9 mm dia.

STα-30 STα-35, WSM G GENERAL Bushing Replacing Tools Application: Use to press out and to press fit the bushing. (1) For small end bushing 162 mm (6.38 in.) 35 mm (1.38 in.) 27 mm (1.06 in.) 35 mm dia. Dia.) 27.90 to 27.95 mm dia.

STα-30 STα-35, WSM G GENERAL Crankshaft Bearing 1 Replacing Tool Application: Use to press out and press fit the crankshaft bearing 1. Extracting tool 135 mm (5.31 in.) 72 mm (2.83 in.) R40 mm (R1.57 in.) 10 mm (0.39 in.) 20 mm (0.79 in.) 20 mm dia. STα-30 STα-35, WSM G GENERAL 2 SPECIAL TOOLS FOR TRACTOR Tie-rod End Lifter Code No: 1 Application: Use for removing the tie-rod end with ease. W1026472 Steering Wheel Puller Code No: 0 Application: Use for removing the steering wheel without damaging the steering shaft. STα-30 STα-35, WSM G GENERAL Clutch Pack Disassembly Tool Code No: 1 Application: This allows easy installation of bi-speed clutch pack spring.

W1073259 Relief Valve Pressure Tester Code No: 5 Application: This allows easy measurement of relief set pressure. (1) Gauge (2) (6) Adaptor C (PS3/8) (1) (2) Cable (1). STα-30 STα-35, WSM G GENERAL NOTE.

Kubota Sta30

The following special tools are not provided, so make them referring to the figure. Adaptor for Flow Meter Application: Use for checking the hydraulic pump for 3P linkage. NOTE. When using, attach with following parts. O-ring: 0 2-8.5 mm dia. STα-30 STα-35, WSM G GENERAL 10.

TIRES 1 TIRE PRESSURE CAUTION. Do not attempt mount a tire. This should be down by a qualified person with the proper equipment. Always maintain the correct tire pressure.

Do not inflate tires above the recommended pressure as shown below. STα-30 STα-35, WSM G GENERAL (1) Front Wheels Front wheel tread cannot be adjusted. IMPORTANT.

Do not turn front discs to obtain wider tread. In setting up the front wheels, make sure that the inflation valve stem of the tires face outward. STα-30 STα-35, WSM G GENERAL 3 TIRE LIQUID INJECTION Auxiliary weights can be used to increase traction force for plowing in fields or clayey ground. Another way is to inject water or another liquid, such as a calcium chloride solution in the tires.

Water must not be used in winter since it freezes at 0 °C (32 °F). STα-30 STα-35, WSM G GENERAL Injection CAUTION.

When a calcium chloride solution is used, cool it before pouring it into the tire. Do not fill tires with water or solution more than 75% of full capacity (to the valve stem level). The following four ways can be used to inject water or a calcium chloride solution into tires. Use with implements which exceed the maximum specifications listed below, or which are otherwise unfit for use with the KUBOTA Tractor may result in malfunctions or failures of the tractor, damage to other property and injury to the operator or others. Any malfunctions or failures of the tractor resulting from use with improper implements are not covered by the warranty. ENGINE KiSC issued 11, 2006 A.

MECHANISM CONTENTS 1. FUEL SYSTEM. 1-M1 1 GOVERNOR. 1-M1 NOTICE For not above-mentioned engine mechanism information, please refer ENGINE MECHANISM WSM (1).

KiSC issued 11, 2006 A. STα-30 STα-35, WSM ENGINE 1. FUEL SYSTEM 1 GOVERNOR The governor serves to keep engine speed constant by automatically adjusting the amount of fuel supplied to the engine according to changes in the load. This engine employs an all-speed governor which controls the centrifugal force of the steel ball (1) weight, produced by rotation of the fuel camshaft (5), and the tension of the governor spring 1 (7) and 2 (8) are balanced. STα-30 STα-35, WSM ENGINE At Idling When the speed control lever is set at the idling position after the engine starts, the governor spring 1 (7) does not work at all and the governor spring 2 (8) does only act slightly. The governor sleeve (2) is pushed leftward by a centrifugal force of steel ball (1). SERVICING CONTENTS 1.

TROUBLESHOOTING.1-S1 2. SERVICING SPECIFICATIONS.1-S4 3. TIGHTENING TORQUES.1-S10 4.

CHECKING, DISASSEMBLING AND SERVICING.1-S11 1 SEPARATING ENGINE FROM TRACTOR.1-S11 2 ENGINE BODY.1-S20 (1) Checking and Adjusting.1-S20 (2) Disassembling and Assembling.1-S22 (3) Servicing.1-S32 3 LUBRICATING SYSTEM.1-S48 (1) Checking.1-S48 (2) Servicing.1-S48. STα-30 STα-35, WSM ENGINE 1.

TROUBLESHOOTING Reference Symptom Probable Cause Solution Page Engine Does Not. No fuel Replenish fuel Start. Air in the fuel system Bleed G-28. Water in the fuel system Change fuel and – repair or replace fuel system. STα-30 STα-35, WSM ENGINE Reference Symptom Probable Cause Solution Page Either Black or Dark. Overload Reduce the load – Gray Exhaust Gas is.

Low grade fuel used Use the specified fuel Observe. Fuel filter clogged Change G-18. STα-30 STα-35, WSM ENGINE Reference Symptom Probable Cause Solution Page Engine Overheated. Engine oil insufficient Replenish.

Fan belt broken or elongated Change or adjust 1-S49. Coolant insufficient Replenish G-26. Radiator net and radiator fin clogged with Clean –. STα-30 STα-35, WSM ENGINE 2. SERVICING SPECIFICATIONS ENGINE BODY Item Factory Specification Allowable Limit Cylinder Head Surface Flatness – 0.05 mm / 500 mm 0.0020 in. Compression Pressure 3.53 to 4.02 MPa / 2.55 MPa / (When Cranking with Starting Motor) 290 rpm 290 rpm. STα-30 STα-35, WSM ENGINE ENGINE BODY (Continued) Item Factory Specification Allowable Limit Valve Timing (Intake Valve) D1463-M Open 0.14 rad.

(8 °) – before T.D.C. Close 0.35 rad. (20 °) – after B.D.C. D1703-M Open 0.21 rad. STα-30 STα-35, WSM ENGINE ENGINE BODY (Continued) Item Factory Specification Allowable Limit Timing Gear Crank Gear to Idle Gear Backlash 0.0415 to 0.1122 mm 0.15 mm 0.00163 to 0.00442 in. Idle Gear to Cam Gear Backlash 0.0415 to 0.1154 mm 0.15 mm 0.00163 to 0.00454 in. STα-30 STα-35, WSM ENGINE ENGINE BODY (Continued) Item Factory Specification Allowable Limit Piston Pin Bore I.D.

25.000 to 25.013 mm 25.05 mm 0.98425 to 0.98476 in. Second Ring to Ring Groove D1463-M Clearance 0.093 to 0.120 mm 0.2 mm 0.00366 to 0.00472 in. STα-30 STα-35, WSM ENGINE ENGINE BODY (Continued) Item Factory Specification Allowable Limit Crankpin to Crankpin Bearing Oil Clearance 0.025 to 0.087 mm 0.2 mm 0.00098 to 0.00343 in. Crankpin O.D. 46.959 to 46.975 mm – 1.84878 to 1.84941 in. Crankpin Bearing I.D.

STα-30 STα-35, WSM ENGINE COOLING SYSTEM Item Factory Specification Allowable Limit Fan Belt Tension 7.0 to 9.0 mm (0.28 to – 0.35 in.) deflection at 98 N (10 kgf, 22 lbs) of force Thermostat Valve Opening 69.5 to 72.5 °C –. STα-30 STα-35, WSM ENGINE 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-9.) Item Nm kgfm ft-lbs Steering wheel mounting nut 48.0 to 56.0 4.9 to 5.7 35.4 to 41.22. STα-30 STα-35, WSM ENGINE 4. CHECKING, DISASSEMBLING AND SERVICING 1 SEPARATING ENGINE FROM TRACTOR Draining Coolant CAUTION. Do not remove the radiator cap when the engine is hot.

Then loosen cap slightly to the stop to relieve any excess pressure before removing cap completely. After running the engine for few minutes, stop it and check the oil level again, if low, add oil prescribed level. IMPORTANT. Use only KUBOTA SUPER UDT fluid-Use of other oils may damage the transmission or hydraulic system. Refer to “LUBRICANTS, FUEL AND COOLANT”. (See page G-8.). STα-30 STα-35, WSM ENGINE Meter Panel and Panel Under Cover 1.

Open the meter panel (1) and disconnect the meter panel connector (2) and hour-meter cable (3). Then remove the meter panel. Remove the sponge.

Disconnect the combination switch connector (4), main switch connector (5), hazard switch connector (6) and position lamp switch connector (8). STα-30 STα-35, WSM ENGINE Power Steering Controller 1.

Disconnect the draining hose (7), power stering delivery hose (3), steering hose RH (4) and steering hose LH (5). Remove the power steering controller (1) with steering pillar (2). (When reassembling). STα-30 STα-35, WSM ENGINE Wire Connectors 1. Remove or disconnect the connectors, terminals as listed below and figures. Remove the harness from each harness clamp. Remove the fuse box mounting screws, and remove the fuse box assembly (10).

(1) Horn (7) Front Wheel Turning Angle Sensor (2) Battery Positive Code. STα-30 STα-35, WSM ENGINE Panel Under Frame 1. Remove the foot cover (2), step stay and plug (1). Remove the panel under frame mounting screw (3) and nut, pull up the panel under frame (4) to remove it.

(When reassembling). STα-30 STα-35, WSM ENGINE Fuel Tank 1. Disconnect the fuel hose (1) at the fuel filter side, then drain fuel completely. Remove the air cleaner assembly. Disconnect the overflow hoses (2) of fuel line. Remove the bonnet rear support (4), shutter plate (3) with fuel tank (5). STα-30 STα-35, WSM ENGINE Hydraulic Pipe 1.

Remove the hydraulic delivery pipe (1) from the 3P hydraulic pump. Loosen the hose band of the joint hose (3) and slide the joint hose (3) to separating the HST drain pipe (2) and inlet pipe (4). STα-30 STα-35, WSM ENGINE Separating the Engine from Clutch Housing 1. Place the jack under the center frame and engine oil pan. Remove the engine mounting screws, bolts and nuts, and separate the engine from the clutch housing. (When reassembling).

STα-30 STα-35, WSM ENGINE 2 ENGINE BODY (1) Checking and Adjusting Compression Pressure 1. Run the engine until it is warmed up.

Kubota Sta 30 Manual

Stop the engine and disconnect the 2P connector from the fuel pump. Remove the air cleaner, the muffler and all injection nozzles. STα-30 STα-35, WSM ENGINE Valve Clearance IMPORTANT. Valve clearance must be checked and adjusted when engine is cold. Remove the head cover, the glow plugs and the timing window cover on the clutch housing. Align the “1TC” mark line on the flywheel and center of timing window so that the No.

STα-30 STα-35, WSM ENGINE Top Clearance 1. Remove the cylinder head.

Move the piston up and stick a strip of fuse on the piston head at three position with grease. Lower the piston and install the cylinder head. (Use a new cylinder head gasket and tighten with a specified tightening torque.) 4. STα-30 STα-35, WSM ENGINE Nozzle Holder Assembly and Glow Plug 1.

Remove the overflow pipe assembly (5). Remove the nozzle holder assemblies (2) using a 21 mm deep socket wrench. Remove the copper gasket and heat seal (3).

STα-30 STα-35, WSM ENGINE Cylinder Head 1. Loosen the pipe clamp, and remove the water return pipe (1). Remove the cylinder head screw in the order of (n) to (a). Lift up the cylinder head to detach. STα-30 STα-35, WSM ENGINE (B) Timing Gears, Camshaft and Fuel Camshaft Injection Pump 1. Remove the stop solenoid (2) and hi-idling body (1).

Remove the engine stop lever (3) and stop solenoid guide (5). Remove the cover (6).

STα-30 STα-35, WSM ENGINE Fan Drive Pulley 1. Lock the flywheel not to turn using the flywheel stopper. Remove the fan drive pulley mounting nut. Remove the fan drive pulley (2) with gear puller. (When reassembling) 137.3 to 156.9 Nm Fan drive pulley mounting Tightening torque 14.0 to 16.0 kgfm.

STα-30 STα-35, WSM ENGINE Camshaft 1. Remove the camshaft set bolts and draw out the camshaft (1). (When reassembling). When installing the idle gear, be sure to align the alignment marks on gears. 23.5 to 27.5 Nm Tightening torque Camshaft set bolt 2.4 to 2.8 kgfm 17.4 to 20.3 ft-lbs. STα-30 STα-35, WSM ENGINE (C) Piston and Connecting Rod Oil Pan and Oil Strainer 1. Remove the oil pan mounting screws.

Remove the oil pan (2) by lightly tapping the rim of the pan with a wooden hammer. STα-30 STα-35, WSM ENGINE Pistons 1. Turn the flywheel and bring the piston to top dead center. Draw out the piston upward by lightly tapping it from the bottom of the crankcase with the grip of a hammer.

STα-30 STα-35, WSM ENGINE Piston Ring and Connecting Rod 1. Remove the piston rings using a piston ring tool (Code No. Remove the piston pin (7), and separate the connecting rod (6) from the piston (5). (When reassembling). STα-30 STα-35, WSM ENGINE (D) Crankshaft Flywheel 1.

Lock the flywheel not to turn using the flywheel stopper. Remove the flywheel screws (1) and flywheel (2). (When reassembling). Apply engine oil to the flywheel screws. Check to see that there are no metal particles left on the flywheel mounting surfaces.

STα-30 STα-35, WSM ENGINE Main Bearing Case Assembly 1. Remove the two main bearing case screws 1, and remove the main bearing case assembly being careful with thrust bearing and crankshaft bearing 2. Remove the main bearing case 1, 2 as above. (When reassembling). STα-30 STα-35, WSM ENGINE Cylinder Head Flaw 1. Prepare an air spray red check (Code No. Clean the surface of the cylinder head with detergent (2).

Spray the cylinder head surface with the read permeative liquid (1). STα-30 STα-35, WSM ENGINE Replacing Valve Guide (When removing) 1. Press out the used valve guide using a valve guide replacing tool. (When installing) 1.

Clean a new valve guide and valve guide bore, and apply engine oil to them. STα-30 STα-35, WSM ENGINE Correcting Valve and Valve Seat NOTE. Before correcting the valve and seat, check the valve stem and the I.D. Of valve guide section, and repair them if necessary. After correcting the valve seat, be sure to check the valve recessing. STα-30 STα-35, WSM ENGINE Free Length and Tilt of Valve Spring 1.

Measure the free length (A) of valve spring with vernier calipers. If the measurement is less than the allowable limit, replace it. Put the valve spring on a surface plate, place a square on the side of the valve spring. STα-30 STα-35, WSM ENGINE Oil Clearance between Tappet and Tappet Guide Bore 1. Measure the tappet O.D. With an outside micrometer.

Measure the I.D. Of the tappet guide bore with a cylinder gauge, and calculate the oil clearance.

STα-30 STα-35, WSM ENGINE Camshaft Side Clearance 1. Set a dial indicator with its tip on the camshaft. Measure the side clearance by moving the cam gear to the front and rear. If the measurement exceeds the allowable limit, replace the camshaft stopper. STα-30 STα-35, WSM ENGINE Cam Height 1. Measure the height of the cam at its highest point with an outside micrometer.

If the measurement is less than the allowable limit, replace the camshaft. 33.90 mm Factory spec.

Cam height of intake 33.85 mm Allowable limit. STα-30 STα-35, WSM ENGINE Oil Clearance between Piston Pin and Small End Bushing 1. Measure the piston pin O.D. Where it contacts the bushing with an outside micrometer.

Measure the small end bushing I.D. With an inside micrometer, and calculate the oil clearance. STα-30 STα-35, WSM ENGINE Clearance between Piston Ring and Groove 1.

Remove carbon from the ring grooves. Measure the clearance between the ring and the groove with a feeler gauge or depth gauge. If the clearance exceeds allowable limit, replace the ring since compression leak and oil shortage result. STα-30 STα-35, WSM ENGINE (D) Crankshaft Side Clearance of Crankshaft 1. Move the crankshaft to the flywheel side. Set a dial indicator to the crankshaft.

Measure the end play by pulling the crankshaft toward the crank gear. STα-30 STα-35, WSM ENGINE Oil Clearance between Crankpin and Crankpin Bearing 1.

Clean the crankpin and crankpin bearing. Put a strip of plastigage (Code No.: 1) on the center of the crankpin in each direction as shown in the figure. STα-30 STα-35, WSM ENGINE Oil Clearance between Crankshaft Journal and Crankshaft Bearing 1 1. Measure the O.D. Of the crankshaft journal with an outside micrometer.

Measure the I.D. Of the crankshaft bearing 1 with an inside micrometer, and calculate oil clearance.

STα-30 STα-35, WSM ENGINE Oil Clearance between Crankshaft Journal and Crankshaft Bearing 2 1. Put a strip of plastigage on the center of the journal.

Install the bearing case and tighten the baring case screws 1 to the specified torque, and remove the bearing case again. STα-30 STα-35, WSM ENGINE Crankshaft Sleeve Wear 1. Check the wear on the crankshaft sleeve (1). If the wear exceeds the allowable limit or when the engine oil leaks, replace the crankshaft sleeve. 0.1 mm Wear of sleeve Allowable limit 0.0004 in. STα-30 STα-35, WSM ENGINE (E) Cylinder Cylinder Wear 1. Measure the I.D.

Of the cylinder at the six positions (see figure) with a cylinder gauge to find the maximum and minimum I.D.’s. Get the difference (Maximum wear) between the maximum and the minimum I.D.’s. STα-30 STα-35, WSM ENGINE 3 LUBRICATING SYSTEM (1) Checking Engine Oil Pressure 1. Remove the engine oil pressure switch, and set a oil pressure tester (Code No.: 2).

Start the engine. After warming up, measure the oil pressure of both idling and rated speeds. STα-30 STα-35, WSM ENGINE Clearance between Rotor and Cover 1.

Put a strip of plastigage (Code No.: 1) onto the rotor face with grease. Install the cover and tighten the screws. Remove the cover carefully, and measure the width of the press gauge with a sheet of gauge.

STα-30 STα-35, WSM ENGINE Thermostat Valve Opening Temperature 1. Suspend the thermostat in the water by a string with its end inserted between the valve and seat. Heating the water gradually, read the temperature when the valve opens and leaves the string. STα-30 STα-35, WSM ENGINE 5 FUEL SYSTEM (1) Checking and Adjusting (A) Injection Pump Injection Timing 1. Remove the injection pipes and stop solenoid.

Set the speed control lever to maximum fuel discharge position. (Reference). Remove the starter motor and turn the flywheel with screwdriver. STα-30 STα-35, WSM ENGINE Fuel Tightness of Pump Element 1. Remove the injection pipes and glow plugs. Install the injection pump pressure tester (1) to the injection pump. Set the speed control lever to the maximum speed position.

STα-30 STα-35, WSM ENGINE (B) Injection Nozzle CAUTION. Check the nozzle injection pressure and condition after confirming that there is nobody standing in the direction the fume goes. If the fume from the nozzle directly contacts the human body, cells may be destroyed and blood poisoning may be caused. STα-30 STα-35, WSM ENGINE (2) Disassembling and Assembling (A) Injection Nozzle Nozzle Holder 1. Secure the nozzle retaining nut (7) with a vise. Remove the nozzle holder (1), and take out parts inside.

(When reassembling). Assemble the nozzle in clean fuel oil. CLUTCH KiSC issued 11, 2006 A. MECHANISM CONTENTS 1. FEATURES.2-M1 2.

OPERATION.2-M2 KiSC issued 11, 2006 A. STα-30 STα-35, WSM CLUTCH 1. FEATURES This tractor is used dry single plate type clutch.

The clutch is located between the engine and transmission and is operated by stepping on the clutch pedal. When the clutch pedal is depressed, the clutch is disengaged and when it is released, the clutch is engaged and power from the engine is transmitted to the transmission. STα-30 STα-35, WSM CLUTCH 2. OPERATION Clutch “Engaged” When the clutch pedal is not depressed, the clutch release bearing (9) and the fingers of diaphragm spring (5) are not connected to each other. Accordingly, the pressure plate (4) is tightly pressed against the flywheel (1) by the diaphragm spring (5). SERVICING CONTENTS 1.

TROUBLESHOOTING.2-S1 2. SERVICING SPECIFICATIONS.2-S2 3.

TIGHTENING TORQUES.2-S3 4. CHECKING, DISASSEMBLING AND SERVICING.2-S4 1 CHECKING AND ADJUSTING.2-S4 2 DISASSEMBLING AND ASSEMBLING.2-S4 (1) Separating Engine from Clutch Housing.2-S4 (2) Separating Clutch Assembly.2-S12 (3) Disassembling Clutch Release.2-S13 3 SERVICING.2-S13 KiSC issued 11, 2006 A. STα-30 STα-35, WSM CLUTCH 1. TROUBLESHOOTING Reference Symptom Probable Cause Solution Page Clutch Drags.

Clutch pedal free travel excessive Adjust 2-S4. Dust on clutch disc generated from clutch Remove rust – disc facing. Release fork broken Replace 2-S13.

STα-30 STα-35, WSM CLUTCH 2. SERVICING SPECIFICATIONS Item Factory Specification Allowable Limit Clutch Pedal Free Travel on 20 to 30 mm – Clutch Pedal 0.78 to 1.18 in.

Safety Switch Setting Position Distance “B” of Approx. 6.0 mm – Safety Switch 0.236 in.

STα-30 STα-35, WSM CLUTCH 3. TIGHTENING TORQUES Tightening torques of screws, bolts and nuts on the table below are especially specified. (For general use screws, bolts and nuts: See page G-9.) Item Nm kgfm ft-lbs Steering wheel mounting nut 48.04 to 56.0 4.9 to 5.7 35.4 to 41.22. After running the engine for few minutes, stop it and check the oil level again, if low, add oil prescribed level.

IMPORTANT. Use only KUBOTA SUPER UDT fluid-Use of other oils may damage the transmission or hydraulic system. Refer to “LUBRICANTS, FUEL AND COOLANT”. (See page G-8.). STα-30 STα-35, WSM CLUTCH Hood, Side Cover and Battery Cord 1. Open the hood (1) and remove the front grille (3).

Disconnect the battery grounding cord (4). Disconnect the head light connectors and remove the side covers (2) and hood (1).

STα-30 STα-35, WSM CLUTCH Accelerator Wire 1. Remove the accelerator wire (1) from hand accelerator lever arm (2). Remove the accelerator wire (1) from speed control lever (3) and holder (4).

IMPORTANT. After assembling, be sure to adjust the accelerator wire to speed control lever to operate the engine maximum speed. STα-30 STα-35, WSM CLUTCH Power Steering Controller 1. Disconnect the draining hose (7), power stering delivery hose (3), steering hose RH (4) and steering hose LH (5).

Remove the power steering controller (1) with steering pillar (2). (When reassembling). STα-30 STα-35, WSM CLUTCH Wire Connectors 1. Remove or disconnect the connectors, terminals as listed below and figures. Remove the harness from each harness clamp. Remove the fuse box mounting screws, and remove the fuse box assembly (10).

(1) Horn (7) Front Wheel Turning Angle Sensor (2) Battery Positive Code. STα-30 STα-35, WSM CLUTCH Panel Under Frame 1. Remove the foot cover (2), step stay and plug (1). Remove the panel under frame mounting screw (3) and nut, pull up the panel under frame (4) to remove it.

(When reassembling). STα-30 STα-35, WSM CLUTCH Fuel Tank 1. Disconnect the fuel hose (1) at the fuel filter side, then drain fuel completely.

Remove the air cleaner assembly. Disconnect the overflow hoses (2) of fuel line. Remove the bonnet rear support (4), shutter plate (3) with fuel tank (5). STα-30 STα-35, WSM CLUTCH Hydraulic Pipe 1.

Remove the hydraulic delivery pipe (1) from the 3P hydraulic pump. Loosen the hose band of the joint hose (3) and slide the joint hose (3) to separating the HST drain pipe (2) and inlet pipe (4). STα-30 STα-35, WSM CLUTCH Separating the Engine from Clutch Housing 1. Place the jack under the center frame and engine oil pan. Remove the engine mounting screws, bolts and nuts, and separate the engine from the clutch housing. (When reassembling). STα-30 STα-35, WSM CLUTCH (3) Disassembling Clutch Release Clutch Release Fork 1.

Remove the set spring (1) from clutch release fork (2) and release hub. Remove the release bearing (3) with release hub (4).

(When reassembling). Set the clutch release fork (2) and release hub with set spring (4) in the correct direction. STα-30 STα-35, WSM CLUTCH Pressure Plate Flatness 1.

Place a straightedge on the pressure plate and measure clearance with a feeler gauge at several points. If the clearance exceeds the allowable limit, replace it. When the pressure plate is worn around its outside and its inside surface only is in contact with the straightedge, replace even if the clearance is within the allowable limit. TRANSMISSION KiSC issued 11, 2006 A. MECHANISM CONTENTS 1.

STRUCTURE.3-M1 2. TRAVELLING SYSTEM.3-M2 1 HYDROSTATIC TRANSMISSION.3-M2 (1) Structure. 3-M2 (2) Hydraulic Circuit. 3-M3 (3) Pump and Motor.3-M4 (4) Operation and Valves. 3-M5 (5) Control Linkage.3-M10 (6) Cruise Control Linkage.

STα-30 STα-35, WSM TRANSMISSION 1. STRUCTURE (1) Hydrostatic Transmission (3) Range Gear Shift Section (5) Mid-PTO Shift Section (7) Bi-speed Turn Section Section (4) Rear PTO Shift Section (6) Front Wheel Drive Section (2) PTO Gear Shift Section KiSC issued 11, 2006 A 3-M1. STα-30 STα-35, WSM TRANSMISSION 2.

TRAVELLING SYSTEM 1 HYDROSTATIC TRANSMISSION (1) Structure Hydrostatic transmission is composed of variable displacement piston pump, fixed displacement piston motor, charge pump and valve system. (1) Neutral Valve (Reverse) (10) Check and High Pressure (2) Neutral Valve (Forward) Relief Valve (Reverse) (3) Trunnion Shaft. STα-30 STα-35, WSM TRANSMISSION (2) Hydraulic Circuit (1) Oil Tank (Transmission Case) (2) Case Relief Valve (3) Variable Displacement Pump (HST Pump) (4) Charge Pump (5) Oil Filter (10 μ) (6) Check and High Pressure Relief Valve (Forward) (7) Check and High Pressure Relief Valve (Reverse) (8) Charge Relief Valve (9) Neutral Valve (Forward). STα-30 STα-35, WSM TRANSMISSION (3) Pump and Motor (1) Swashplate (4) Oil (6) Piston A Pump (2) Piston (5) Cylinder (7) Swashplate B Motor (3) Cylinder Pump and motor cylinder, each containing pistons, are connected by lines. Cylinders and lines are filled with oil.

Pistons ride against swashplates(1) and (7) located in pump and motor. STα-30 STα-35, WSM TRANSMISSION (4) Operation and Valves Neutral Position (1) Oil Cooler (2) Charge Relief Valve (3) HST Pump (Variable Discharge Pump) (4) Oil Filter (10 μ) (5) Check and High Pressure Relief Valve (Forward) (6) Check and High Pressure Relief Valve (Reverse) (7) Charge Pump (8) HST Motor (Fixed Discharge.