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Kubota B3030, B3000, B3300 - Transmission
Kubota B3030, B3000, B3300 - Hydrostatic
Transmission Structure
Hydrostatic transmission is composed of variable displacement piston
pump, fixed displacement piston motor and valve system.
1 - Cylinder Block (Motor), 2 - Piston, 3 - Thrust Collar, 4 - Motor
Shaft, 5 - Retainer Plate, 6 - Thrust Collar, 7 - Pump Shaft, 8 -
Variable Swashplate, 9 - Piston, 10 - Cylinder Block (Pump), 11 - Charge
Relief Valve, 12 - Needle Bearing, 13 - Valve Plate
Front Case
1 - Flywheel, 2 - Clutch Housing, 3 - Steel Plate, 4 - Clutch Shaft, 5 -
Oil Seal, 6 - Ball Bearing, 7 - Oil Seal, 8 - 28T-28T Front Wheel Drive
Shaft 1, 9 - Front Wheel Drive Shaft 2, 10 - 24T Front Wheel Drive Shaft
3, 11 - Bi-Speed Turn Clutch, 12 - Front Mission Cover, 13 - Propeller
Shaft, C - To HST, D - From Front Wheel Drive Gear Section
In Kubota B3030, B3000, B3300 tractor, clutch disk is not installed. The
steel plate is installed on the clutch shaft. Power from the engine is
transmitted through the steel plate to the clutch shaft and HST pump
shaft.
Kubota B3030, B3000, B3300 - Hydrostatic
Transmission Linkage
Bi-Speed Turn Linkage
Bi-Speed Turn lever is connected to the Bi-Speed rod and the Bi-Speed
Turn ON/OFF shift shaft. The left bevel gear case of the front axle is
connected to the front Bi-Speed Turn shift shaft with a Bi-Speed rod 2.
1 - Bi-Speed Rod 1, 2 - Front Mission Cover, 3 - Bi-Speed Turn ON/OFF
Shift Shaft, 4 - Bi-Speed Turn Shift Shaft, 5 - Bi-Speed Rod 2, A -
Connected to the Left Bevel Gear Case
Bi-Speed Turn Engaged
When the Bi-Speed Turn lever is shifted to “ON” position, the Bi-Speed
rod 1 (1) is pushed down and the Bi-Speed Turn ON/OFF shift shaft (2) is
rotated counterclockwise. It is kept ”ON”. When steering the steering
wheel to “Left” or “Right”, the Bi-Speed rod 2 connected to the left
bevel gear case is pulled. The Bi-Speed Turn shift shaft (3) is rotated.
At this time, hydraulic oil from the pump port enter to the Bi-Speed
clutch shaft through both the Bi-Speed Turn shift shaft (3) and the
Bi-Speed ON/OFF shift shaft (2). The Bi-Speed Turn is engaged.
Bi-Speed Turn Disengaged
When the Bi-Speed Turn lever is shifted to “OFF” position, the Bi-Speed
rod 1 (1) is pushed up and the Bi-Speed Turn ON/OFF shift shaft (2) is
rotated clockwise. It is kept ”OFF”. When steering the steering wheel to
“Straight”, the Bi-Speed rod 2 connected to the left bevel gear case is
not pulled. The Bi-Speed Turn shift shaft (3) is kept to “OFF” position.
At this time, hydraulic oil from the pump port does not enter to the
Bi-Speed Turn ON/OFF shift shaft. The Bi-Speed Turn is disengaged.
Kubota B3030, B3000, B3300 - Cruise Control Linkage
1 - Return Spring, 2 - Cruise Control Lever, 3 - Cruise Lock 1, 4 -
Release Rod, 5 - Roller, 6 - Neutral Holder, 7 - Trunnion Shaft, 8 - HST
Pedal, 9 - HST Lever, 10 - Cruise Lock 2, 11 - Brake Rod, 12 - Cruise
Rod, 13 - HST Plate, 14 - HST Lever, 15 - Brake Spring
Cruise Control “ON” Position
When depressing the HST pedal (8) to “Forward”, the HST lever (14), the
cruise rod (12) and the cruise lock 2 (10) moves like the arrow shown in
the pictures. And when the cruise control lever (2) is set to the
desired position, the cruise lock (1) is locked to the cruise lock 2
(10) and the travelling speed is held to the desired speed.
Cruise Control “OFF” Position
When depressing the brake pedals (9), the release rod (4), the cruise
control lever (2) and the cruise lock 1 (3) moves like the arrows shown
in the pictures. And the cruise lock 1 release from the cruise lock 2
(10). Cruise lock is changed from “ON” to “OFF” position. Since the
cruise lock is kept “OFF”, the neutral holder turns counterclockwise,
and the roller is returned to “Neutral” position. The HST pedal (8) also
returns to “Neutral“ position and the tractor stops.
Front Wheel Drive Section
1 - Front Wheel Drive Lever, 2 - Transmission Case, 3 - Shifter, 4 -
Front Wheel Drive Shaft, 5 - 19T Shifter Gear, 6 - 14T Gear, 7 - 17T
Gear, 8 - 25T-31T Gear, 9 - 6T Bevel Pinion Shaft, A - 4 Wheel Drive
Position, B - 2 Wheel Drive Position, F - Power to Front Wheels, R -
Power to Rear Wheels
Kubota B3030, B3000, B3300 Tractor - Hydraulic
PTO Clutch
Rear PTO
When the PTO shift lever is set to "REAR PTO" (R) position, the PTO
shift lever pushes the control rod. The control rod pushes the PTO shift
arm. In this state, the PTO shift arm shifts the PTO shifter forward.
The inner spline of the PTO shifter meshes the independent PTO shaft
spline. Power is transmitted from the independent PTO clutch to the rear
PTO shaft as follows. Independent PTO clutch - PTO shifter - Independent
PTO shaft - Rear PTO shifter - Rear PTO shaft.
Rear PTO / Mid PTO
When the PTO shift lever is set to "REAR PTO / MID PTO" (R/M) position,
the PTO shift lever pulls the control rod. The control rod pulls the PTO
shift arm. In this state, the PTO shifter keeps its position between the
independent PTO shaft spline and the 25T mid gear spline. In this
position, the inner spline of the PTO shifter meshes both independent
PTO shaft spline and the 25T and gear spline. Power is transmitted from
the independent PTO clutch to both the rear PTO shaft and the mid PTO
shaft as follows. Rear PTO Section: Independent PTO Clutch - PTO shifter
- Independent PTO Shaft - Rear PTO shifter - Rear PTO shaft. Mid PTO
Section: Independent PTO Clutch - PTO shifter - 25T mid gear - 26T gear
on front wheel drive shaft - 17T-26T mid gear - 30T gear - Mid PTO shaft
17T.
Mid PTO
When the PTO shift lever is set to "MID-PTO" (M) position, the PTO shift
lever pulls the control rod. The control rod pulls the PTO shift arm. In
this state, the PTO shift arm shifts the PTO shifter reverse. The inner
spline of the PTO shifter meshes the 25T Mid PTO gear spline. On the
other hand, the range gear shifter arm turns the rear PTO control plate
counterclockwise and turns the rear PTO arm counterclockwise. Since the
rear PTO arm is turned counter clockwise, the rear PTO shifter is pushed
forward. Then, the rear PTO shifter meshes the rib of the transmission
case. In this state, the rear PTO brake shifter prevents the independent
PTO shaft from rotating itself. Power is transmitted from the
independent PTO clutch to the Mid PTO shaft as follows. Independent PTO
clutch - PTO shifter - 25T mid gear - 26T gear - 17T-26T mid gear - 30T
gear - Mid PTO shaft.
Kubota B3030, B3000, B3300 - Rear Axle
Removing Rear Wheels and Rear Axle
Support the tractor sub-frame with a jack. Remove the rear wheel
mounting bolts and the nuts. Remove the rear wheel. Disconnect the brake
rods. Remove the rear axle case mounting bolts. Remove the rear axle.
Apply liquid gasket to the joint face of the rear axle case and the
differential gear case.
Differential Lock Shift Fork
Remove the spring. Draw out the differential lock shift lock clutch and
the differential lock shift fork. Remove the external cir-clip. Remove
the transmission oil filter bracket.
Rear Axle Shaft
Remove the fork rod. Remove the ball bearing with a puller. Remove the
gear. Remove the brake shaft assembly. Tap out the rear axle shaft with
a rubber hammer to the outside. Tap in the ball bearing to the rear axle
case.
Ball Bearing Checking
Hold the inner race, and push and pull the outer race in all directions
to check for wear and roughness. Apply transmission fluid to the
bearing, and hold the inner race. Then, turn the outer race to check
rotation. If there is any defect, replace it.
Kubota B3030, B3000, B3300 - HST Transmission
Removal
Transmission Case Separating
Disconnect the brake rods. Disconnect the code bands from the wiring
harness. Disconnect the couplers from the HST neutral switch and the PTO
neutral switch. Separate the wiring harness from the transmission case.
Loosen the pipe bands. Disconnect the hydraulic inlet pipe. Disconnect
the independent PTO valve delivery pipe. Disconnect the hydraulic
cylinder delivery pipe. Hoist the transmission case and the main frame.
Support the transmission with a jack. Remove the main frame mounting
bolts. Separate the transmission assembly from the main frame. After
separating the transmission, remove the rear wheels and the transmission
outer parts installed to the transmission.
HST Assembly
Remove the HST mounting bolts. Separate the HST assembly from the
transmission. Install the O-ring to the transmission case. Apply liquid
gasket to the groove of the transmission case.
Plate Push Rod, Neutral Arm and Neutral Holder
Remove the plate push rod. Remove the spring. Remove the neutral arm
mounting bolt. Loosen the bolt of the neutral holder. Remove the neutral
holder.
Center Section 1
Remove the center section mounting hex. bolts. Separate the HST housing
from the center section. Use a new gasket. Install the poppet to the
center section. Don't drop the spring. Check the knock pin. Hold the
gasket with the hex. bolts not to drop the gasket.
Valve Plates
Pushing the valve plate against the anchor pin, lift the valve plate to
remove. Remove the valve plate. Remove the valve plate. Install the
groove the valve plates to the anchor pins securely.
Oil Seals and Needle Bearings
Remove the needle bearing. Remove the oil seals. After checking or
changing the oil seals, apply the bearing with hydrostatic transmission
oil and the oil seal with grease.
Check and High Pressure Relief Valve and Neutral Valve
Remove the valve plug with a hex. wrench. Remove the spring and the
valve. Remove the neutral valve body. Remove the pin from the neutral
valve body. Remove the plug with 2.5 mm hex. wrench. Push the neutral
valve with 2.5 mm hex. wrench not to damage it. Take out the inner parts
from the neutral valve body.
HST Housing Case Cylinder Blocks
Remove the cylinder blocks from the pump shaft and the motor shaft.
Remove the cir-clip and spring from the cylinder block. Install the
poppet to the center section, not to drop it. Install the spring to the
HST housing side.
Piston and Retainer Plate
Remove the pistons with the retainer plates. Install the piston to its
original position of the cylinder block. Check the direction of the
thrust collar. If the direction of the thrust collar is wrong, HST will
not be operated properly.
Motor Shaft and Pump Shaft
Remove the internal cir-clip from the HST housing. Remove the cover with
an O-ring. Remove the motor shaft with the ball bearing from the HST
housing. Remove the external cir-clip from the motor shaft. Remove the
ball bearing from the motor shaft. Pump Shaft - Remove the internal
cir-clip from the HST housing. Remove the oil seal from the HST housing.
Remove the external cir-clip from the pump shaft. Remove the internal
cir-clip from the HST housing. Remove the pump shaft to the cylinder
block side. Replace the used oil seal with a new one.
Trunnion Shaft and Charge Relief Valve
Remove the internal cir-clip from the HST housing. Remove the internal
cir-clip from the HST housing. Strike out the trunnion shaft slightly
with a plastic hammer to the left side not to damage the o-rings. Take
out the cover with o-ring. Take out the thrust collar using air blower.
Check the O-rings for damage. Check the spring for breakage and wear. If
it is unusual, replace it.
Kubota B3030, B3000, B3300 - Independent PTO
Clutch
PTO Clutch Case
Remove the external cir-clip from the spline boss. Remove the internal
cir-clip from the PTO clutch case. Remove the clutch disks and the
clutch plates from the PTO clutch case. Remove the ball bearing from the
PTO clutch case with a puller. When removing the cir-clip, use an
adequate size snap ring pliers.
PTO Clutch Spring
Set the PTO clutch spring compressor to the PTO clutch case. Tighten the
nut and remove the external cir-clip. Remove the spring collar and the
PTO clutch spring.
PTO Clutch Disks and Brake
After removing the inner cir-clip from the PTO clutch case, remove the
pressure plate. Remove the clutch disks and clutch plates. Remove the
external cir-clip from the spline boss. Remove the brake plate, the
brake disks and the brake plate. After removing the external cir-clip
and the spring. Install the parts to the original positions.
Spline Boss Cir-clip
Push the cir-clip with a small screw driver through the small hole of
the spline boss. Lift the cir-clip with a screw driver not to damage it.
Install the cir-clip holding it by hands.
PTO Shaft
Remove the thrust bearing and the PTO shifter not to damage the seal
rings located at the PTO shaft front side. Remove the seal rings located
at the PTO shaft rear side. Remove the ball bearing with a puller. Check
all seal rings. If the seal ring is damaged, replace it. Check the
direction of the thrust bearing and install the thrust bearing.
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KUBOTA TRACTORS SPECIFICATIONS |
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KUBOTA ENGINES DATA AND SERVICE SPECS |
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KUBOTA FRONT END LOADERS |
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KUBOTA TRACTORS TROUBLESHOOTING | ||||
L235 | L2501 | L2550 | L275 | L3110 |
L3301 | L35 | L3710 | L3901 | L4310 |
L5030 | M4700 | M5700 | M6040 | M6800 |
M8200 | M8540 | M9000 | MX5100 | MX5200 |