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Kubota B2050, B2350, B2650 - Transmission

Kubota B2050, B2350, B2650 - Manual Transmission

Manual Transmission (without Bi-Speed Turn Model): 1 - Main Clutch Section, 2 - Main Gear Shift Section, 3 - Shuttle Shift Section, 4 - Mechanical PTO Clutch Section, 5 - Range Gear Shift Section, 6 - Differential Gear Section, 7 - Rear PTO Gear Section, 8 - Mid-PTO Gear Section, 9 - Front Wheel Drive Gear Section, A - From Front Case, B - To Front Axle

Manual Transmission (with Bi-Speed Turn Model): 1 - Main Clutch Section, 2 - Main Gear Shift Section, 3 - Shuttle Shift Section, 4 - Mechanical PTO Clutch Section, 5 - Range Gear Shift Section, 6 - Differential Gear Section, 7 - Rear PTO Gear Section, 8 - Mid-PTO Gear Section, 9 - Front Wheel Drive Gear Section, 10 - Bi-Speed Turn Gear Section, A - From Front Case, B - To Bi-Speed Turn Gear Section

Manual Transmission (with Bi-Speed Turn and without Mid-PTO Model): 1 - Main Clutch Section, 2 - Main Gear Shift Section, 3 - Shuttle Shift Section, 4 - Mechanical PTO Clutch Section, 5 - Range Gear Shift Section, 6 - Differential Gear Section, 7 - Rear PTO Gear Section, 8 - Front Wheel Drive Gear Section, 9 - Bi-Speed Turn Gear Section, A - From Front Case, B - To Bi-Speed Turn Gear Section

Main Gear Shift Section

Main shift section consists of three speeds.

1 - First Shift Shaft, 2 - 13T F1 Gear, 3 - 23T F2 Gear (Shifter), 4 - 29T F3 Gear, 5 - 15T-32T-26T-13T Shaft, 6 - 15T Gear, 7 - 30T F1 Gear, 8 - Shuttle Shaft, 9 - 32T Gear, 10 - 26T Gear

1st Speed Gear - The 23T F2 gear (shifter) (3) slides to the engine side. The 23T F2 gear (shifter) (3) meshes to the 13T F1 gear (2). The power is transmitted as follows. First shift shaft (1) - 23T F2 gear (shifter) (3) - 13T F1 gear (2) - 30T F1 gear (7) - 15T-32T-26T-13T shaft (5).

2nd Speed Gear - The 23T F2 gear (shifter) (3) meshes to the 32T gear (9) of the 15T-32T-26T-13T shaft (5). The power is transmitted as follows. First shift shaft (1) - 23T F2 gear (shifter) (3) - 32T gear (9) / 15T-32T-26T-13T shaft (5).

3rd Speed Gear - The 23T F2 gear (shifter) (3) slides to the mechanical PTO clutch side. The 23T F2 gear (shifter) (3) meshes to the 29T F3 gear (4). The power is transmitted as follows. First shift shaft (1) - 23T F2 gear (shifter) (3) - 29T F3 gear (4) - 26T gear (10) / 15T-32T-26T-13T shaft (5).

Shuttle Gear Shift Section

The power shifted in the main gear shift section is transmitted from the 15T-32T-26T-13T shaft (2) to the shuttle shaft (3). The shuttle shift gears are the sliding mesh gears. The reverse shaft is the front wheel drive shaft (8). The 27T gear (9) on the front wheel drive gear (8) is a reverse gear.

1 - First Shift Shaft, 2 - 15T-32T-26T-13T Shaft, 3 - Shuttle Shaft, 4 - 28T Gear, 5 - Shifter, 6 - 24T Gear, 7 - 13T Gear, 8 - Front Wheel Drive Shaft, 9 - 27T Gear, F - Forward, R - Reverse, A - To High-Low Range Gear Section

Forward - When shifting the shuttle lever to “Forward”, the shifter (5) slides to the 28T gear side. The shifter (5) meshes to the 28T gear (4). The power is transmitted as follows. 15T-32T-26T-13T shaft (2) / 15T gear (2) - 28T gear (4) - shifter (5) - shuttle shaft - Hi-Low range gear section.

Reverse - When shifting the shuttle lever to “Reverse”, the shifter (5) slides to the 24T gear side. The shifter is transmitted as follows. 15T-32T-26T-13T shaft (2) / 13T gear (7) - 27T gear (9) on the front wheel drive shaft (8) - 24T gear (6) - shifter (5) - shuttle shaft (3) - High-low range gear section.

Range gear shift section

Range gear shift lever (1) is located at left side fender. Range gear shift lever (1) can select three speed range, low speed, mid speed and high speed. Range gear shift lever (1) and 18T shifter gear (10) are linked with range shift arm (3) and range shift fork (2) etc. Three range gear shifts are selected by shifting the 18T shifter gear (10) on the sub shaft (8) to 17T gear (6) and 25T-31T gear (7) on 6T bevel pinion shaft (4).

1 - Range Gear Shift Lever, 2 - Range Shift Fork, 3 - Range Shift Arm, 4 - 6T Bevel Pinion Shaft, 5 - 13T Gear (for Front Wheel Drive), 6 - 17T Gear, 7 - 25T-31T Gear, 8 - Sub Shaft, 9 - 26T Gear, 10 - 18T Shifter Gear, 11 - 12T Gear, L - LOW Range, M - MID Range, N - Neutral Position, H - HIGH Range

Low Speed Position - Sub shaft (8) - 18T shifter gear (10) - 12T gear (11) - 31T of 25T-31T gear (7) - 6T bevel pinion shaft (4).

Middle Speed Position - Sub shaft (8) - 18T shifter gear (10) - 25T of 25T-31T gear (7) - 6T bevel pinion shaft (4).

High Speed Position - Sub shaft (8) - 18T shifter gear (10) - 26T gear (9) - 17T gear (6) - 6T bevel pinion shaft (4).

Kubota B2050, B2350, B2650 Tractor - Power Take Off

Mechanical PTO Clutch

The PTO shift lever (1) is located at left side fender. The PTO positions are selected to three positions, the “Rear PTO” position (R), the “Rear PTO/ the mid-PTO” position (R/M) and the “Mid-PTO” position (M). The PTO section is separated to two sections. The front PTO section is located in the main speed shift case. The rear PTO is the mechanism PTO assembly and is located in the transmission case. The shifter (17) is connected mechanically to the PTO select lever. When the mechanical PTO clutch lever is shifted to “ON (Engaged)” position, the mechanical PTO clutch lever sides front and meshes to the one-way clutch spline boss (21). Since the PTO brake spline boss (12), the power is transmitted from the one-way clutch spline boss through the shifter (10) to the PTO brake spline boss (12).

1 - First Shift Shaft, 2 - Collar (1.8), 3 - Overrunning Clutch Spring, 4 - One-way Clutch Cam, 5 - Bearing Holder, 6 - Cir-clip, 7 - Ball Bearing, 8 - Cir-clip, 9 - One-way Clutch Spline Boss, 10 - Shifter (PTO ON/OFF), 11 - PTO Brake Spring, 12 - PTO Brake Spline Boss, 13 - Brake Plate 2, 14 - Brake Disk, 15 - Brake Plate 3, 16 - Brake Plate 1, 17 - PTO Shifter, 18-25T Mid-gear, 19 - Collar (20), 20 - Ball Bearing, 21 - Needle Bearing, 22 - Thrust Ball Bearing, 23 - Cir-clip, 24 - Thrust Collar, 25 - Needle Bearing, 26 - Cir-clip, 27 - PTO Clutch, 28 - PTO Shift Lever, 29 - PTO ON/OFF Shift Folk, a - One-way Clutch Section, A - Connected to the PTO Select Lever, R - REAR PTO position, R/M - REAR PTO / MID PTO position, M - MID-PTO Position

PTO Brakes

When the mechanical PTO clutch lever is shifted to “OFF (Disengaged)” position, the shifter slides to the PTO brake spring side. The shifter does not mesh to the one-way clutch spline boss, and the power is not transmitted from the one-way clutch spline boss (9) to the PTO brake spline boss. Since the PTO brake spring pushed the brake prates and the PTO brake disks, the PTO brake is engaged at this moment.

Kubota B2050, B2350, B2650 Tractor - Rear PTO

When the PTO shift lever is set to “Rear PTO” position (R), the PTO shifter slides to “Rear PTO” position (R). The PTO shifter meshes to the spline of the PTO clutch shaft. The power is transmitted from the first shift shaft to the PTO clutch shaft as follows. First shift shaft - One-way clutch cam - One-way clutch spline boss - shifter (PTO ON/OFF) - PTO brake spline boss - PTO shifter - PTO clutch shaft.

Rear PTO / Mid PTO

When the PTO shift lever is set to “Rear PTO/Mid-PTO” position, the PTO shifter slides to “Rear PTO/Mid-PTO” position (R/M). The PTO shifter meshes to both the spline of the PTO clutch shaft and the spline of the 25T mid-PTO gear. The power is transmitted from the first shift shaft to both the rear PTO and the mid-PTO as follows. To Rear PTO: First shift shaft - One-way clutch cam - One-way clutch spline boss - shifter (PTO ON/OFF) - PTO brake spline boss - PTO shifter - PTO clutch shaft - to rear PTO. To Mid PTO: First shift shaft - One-way clutch cam - One-way clutch spline boss - shifter (PTO ON/OFF) - PTO brake spline boss - PTO shifter - 25T mid-gear - 26T gear - to mid-PTO.

Mid PTO

When the PTO shift lever is set to “Mid-PTO” position, the PTO shifter slides to “Mid-PTO” position (M). The PTO shifter meshes to the spline of the 25T mid-gear. The power is transmitted from the first shift shaft to the mid-PTO.

Kubota B2050, B2350, B2650 - Clutch

1 - Engine Flywheel, 2 - Clutch Disc, 3 - Clutch Cover, 4 - Pressure Plate, 5 - Diaphragm Spring, 6 - Clutch Rod, 7 - Clutch Release Fork, 8 - Clutch Release Bearing, 9 - Clutch Release Hub, 10 - Clutch Shaft, 11 - Pressure Plate Assembly

Kubota B2050, B2350, B2650 - Transmission Service

Bi-Speed Turn Clutch

Clutch Disk and Clutch Plate - Measure the clutch disk thickness with a Vernier calipers. Measure the clutch plate thickness with a Vernier calipers. If the thickness is less than the allowable limit, replace it. If the bearing is worn, replace it. Bi-Speed Turn clutch disk thickness - 1.70 to 1.90 mm (0.067 to 0.075 in). Bi-Speed Turn clutch disk plate thickness - 1.95 to 2.05 mm (0.0768 to 0.0807 in).

Mechanical PTO Clutch

PTO Clutch Shaft - Check the needle bearings. Check the needle bearing surfaces of the PTO clutch shaft. Check the needle bearing surfaces of the one-way clutch spline boss, the PTO brake spline boss and the 25T mid-PTO gear. If the PTO clutch shaft is rough or grooved, replace it. If the needle bearing is wore, replace it. The one-way clutch spline boss, the PTO brake spline boss or the 25T mid-PTO gear is worn, replace it.

PTO Brake Disk and Brake Plate 1

Measure the PTO brake disk thickness with a Vernier calipers. Measure the brake plate thickness with a Vernier calipers. If the thickness is less than the allowable limit, replace it. PTO brake disk thickness - 1.70 to 1.90 mm (0.067 to 0.075 in). Mechanical PTO brake plate 1 thickness - 1.95 to 2.05 mm (0.0768 to 0.0807 in).

Kubota B2050, B2350, B2650 - Mechanical PTO Clutch Assembly

Separating Transmission Case from Differential Case

Remove the transmission mounting bolts and nuts. Separate the transmission case from the differential case. Install the coupling to the mechanical PTO clutch shaft. Apply the liquid gasket. Tighten the transmission mounting bolts and the nuts to the specified torque.

Removing One-Way Clutch Spline Boss

Remove the circlip from the PTO clutch shaft. Remove the one-way clutch spline boss with the bearing. Remove the needle bearing and the thrust ball bearing.

Removing PTO ON-OFF Shift Fork and PTO Shift Arm

Remove the circlip from the PTO clutch shaft. Remove the circlip the PTO ON-OFF arm shaft. Remove the shifter and the PTO clutch spring. Remove the bolt and the washer from the transmission case. Remove the PTO shift arm. Install the PTO cotter to the groove of the PTO shifter securely. Install the ball and the spring to the transmission case using the special ball guide.

Removing and Disassembling Mechanical PTO Clutch Assembly

Remove the rear PTO shifter from the PTO clutch shaft. Disassemble the mechanical PTO clutch assembly. Check the mechanical PTO clutch assembly parts the damage and wear, replace it.

Kubota B2050, B2350, B2650 Tractor - Separating Engine From Clutch housing

Draining Transmission Fluid

Place oil pan underneath the transmission case, and remove the drain plugs. Drain the transmission fluid. Reinstall the drain plug. Fill new oil from port after remaining the filling plug up to the upper notch on the dipstick. After running the engine for new minutes, stop it and check the oil level again, it low, add oil prescribed level. Transmission fluid capacity - Manual transmission (without Bi-Speed Turn) - 15 L. Manual transmission (with Bi-Speed Turn) - 16.5 L.

Bonnet, Side Cover and Battery Cord

Open the bonnet and remove the front grille. Disconnect the battery negative cord. Disconnect the head light connectors and remove the bonnet side covers. When disconnecting the battery cords, disconnect the grounding cord first. When connecting, positive cord first.

Hydraulic Hoses from Power Steering Cylinder

Disconnect the hydraulic hoses from the power steering cylinder. Removing the snap pin and disconnect the bi-speed rod. Fuel - Disconnect the fuel hose from the fuel filter. Drain the fuel to the fuel tank completely.

Steering Wheel, Meter Panel, Shuttle Lever and Panel Lower Cover

Remove the steering wheel cap. Remove the steering wheel mounting nut. Remove the steering wheel with a steering wheel puller. Remove the accelerator lever grip and the steering boot. Disconnect the hour meter cable and wiring harness connectors. Remove the meter panel not to damage with the steering shaft. Remove the shuttle lever. Remove the panel lower cover.

Fuel Tank

Disconnect the leads from the fuel tank. Disconnect the overflow hoses from the fuel tank. Remove the shutter plate and the fuel tank.

Key Stop Solenoid and Hydraulic Delivery Pipe

Remove the key stop solenoid connector. Remove the engine stop solenoid using a small size ratchet handle, the extension joint, the universal joint and the thinner socket (10 mm). Remove the hydraulic delivery pipe mounting nuts. Slide the hydraulic delivery pipe. Loosen the hose band. Disconnect the suction hose from the hydraulic pump. Apply the liquid gasket to the joint face of the key stop solenoid and the engine.

Steps (4-cylinder Engine, ROPS Model)

Remove the bolts and the nut. Remove the brake spring from the step (RH). Remove the brake spring and the clutch spring from the step (LH).

Sub-Frames (4-cylinder Engine Model)

Place the rigid jack under the rear axle shaft. Remove the transmission oil filter cartridge. Loosen the sub-frame mounting bolts. Remove the sub-frames.

Separating Engine with Front Axle

Reinstall the rear tires. Support the transmission with a disassembling stand. Hook the engine with a hoist. Place the disassembling stand under the main frame. Disconnect the power steering hoses. Loose the hydraulic inlet hose band. Disconnect the hydraulic inlet hose from the hydraulic pump. Disconnect the hydraulic delivery pipe from the hydraulic pump. Disconnect the wiring leads from the alternator, the engine oil pressure switch and the starter motor. Disconnect the wiring harness and the power steering hoses from the engine body. Remove the docking bolts between the engine and the front case. Align the spline between the front wheel drive shaft and the universal joint securely.

Separating the Clutch Assembly

Remove the clutch assembly from the flywheel. Direct the shorter end of the clutch disc boss toward the flywheel. Apply molybdenum disulphide to the splines of clutch disc boss. Install the pressure plate, noting the position of straight pins. Align the center of clutch disc and flywheel by inserting the clutch center tool. Do not allow grease and oil on the clutch disc facing.

Clutch and Clutch Release Fork

Remove the external snap ring at the end of clutch rod shaft and remove the clutch release fork and the release bearing with release bearing holder. Set the clutch release fork and the release bearing with the release folk spring in the correct direction.

KUBOTA TRACTORS TROUBLESHOOTING
L235	L2501	L2550	L275	L3110
L3301	L35	L3710	L3901	L4310
L5030	M4700	M5700	M6040	M6800
M8200	M8540	M9000	MX5100	MX5200