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| Illustration 1 | g00509659 |
Three-point hitch and quick hitch | |
The three-point hitch is standard equipment on the machine. The three-point hitch is actuated by a single acting three-point hitch control valve. The three-point hitch control valve is equipped with a pilot-operated check valve. The three-point hitch control valve is operated by an electrohydraulic control.
The three-point hitch is operated from the side console. The following items are used in order to control the three-point hitch: three-point hitch control lever, three-point hitch lower rate control, height limit control, three-point hitch raise/lower switch, external position control switch and draft/position control knob (if equipped). These switches and controls send signals to both the Right Hand Control Module RHC and the Chassis Control Module CCM. The control modules send a pulse width modulated signal that is DC current to the two solenoids on the hitch control valve.
The amount of current that is applied to the solenoids controls the rate of the lowering and raising of the three-point hitch. The rate is not controlled by the hydraulic flow.
The three-point hitch linkage on this machine is rated for category lll usage. Category ll and category lllN implements can be used on this machine when you convert the linkage. The standard lift capacity of the three-point hitch is 5669 kg (12,500 lb). An optional configuration raises the lift capacity to 6802 kg (15,000 lb).
Note: The lift capacity of the three-point hitch is rated at 610 mm (24 inch) behind the ball ends.
Three-Point Hitch Controls
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| Illustration 2 | g00508491 |
Three-point hitch controls (1) Three-point hitch raise/lower switch (2) Adjustable depth stop (3) Three-point hitch control lever (4) Three-point hitch status display (5) Draft/position control knob (if equipped) (6) Height limit control (7) Three-point hitch lower rate control | |
Height of the implement and depth of the implement is controlled by three-point hitch control lever (3). The three-point hitch control lever activates the external position control switches when you push the lever fully forward. Pull the lever in the rearward direction in order to raise the hitch. Push the lever in the forward direction in order to lower the hitch.
An adjustable depth stop (2) is located on the right side of three-point hitch control lever (3). Depth stop (2) sets the lower travel of the lever. In order to adjust, loosen the knob that is on depth stop (2) and slide the stop in order to contact the lever at the desired position. Tighten the knob once the depth stop is in the correct position. If necessary, the three-point hitch control lever can be pulled sideways in order to bypass the depth stop.
Note: When a machine is equipped with the optional electronic draft control, the full down position of the three-point hitch control lever is not recommended for implements that engage the soil.
Height limit control (6) will limit the maximum height for the three-point hitch. Use height limit control (6) in order to prevent large implements from striking the rear of the cab. Rotate the knob in the clockwise direction in order to increase the lift height. Rotate the knob in the counterclockwise direction in order to decrease the lift height.
Rotate knob (6) fully in the counterclockwise direction in order to set height. The hitch will raise approximately to 1/2 of the full upper position. Pull the three-point hitch control lever fully in the rearward direction. Slowly turn the height limit control in the clockwise direction in order to raise the implement. There should be 100 mm (4 inch) of clearance between the machine and implement.
Three-point hitch lower rate control (7) is used in order to vary the speed of lowering the three-point hitch. Rotate three-point hitch lower rate control (7) in the clockwise direction in order to increase the rate of lowering. Rotate three-point hitch lower rate control (7) in the counterclockwise direction in order to decrease the rate of lowering. The three-point hitch lower rate control is identified with a decal that has six positions. Position "1" is the slowest rate of drop. Position "6" has the fastest rate of drop.
Note: The three-point hitch lower rate control only affects the three-point hitch when the implement is not engaging the ground.
Three-point hitch raise/lower switch (1) allows the operator to rapidly raise the implement to the position that is set by the height limit control. Switch (1) allows the operator to lower the implement to the position that is set by the three-point hitch control lever. Pressing the front of the switch lowers the implement and pressing the rear of the switch raises the implement.
Three-point hitch raise/lower switch (1) allows the operator to raise the implement at the end of a row. Once the turn is completed, the operator can return the implement to the same position.
Note: Three-point hitch raise/lower switch (1) should be placed in the RAISE position when you are transporting equipment. Three-point hitch raise/lower switch (1) should be placed in the WORK position in order for three-point hitch control lever (3) to function.
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| Illustration 3 | g00636527 |
Three-point hitch raise/lower switch that is equipped with a FLOAT position | |
The machine may be equipped with a three-point hitch raise/lower switch that has a FLOAT position. The three-point hitch may be lowered below the depth that is set by the three-point hitch control lever. Press and hold the front of switch (28) in order to allow the three-point hitch to float. This will not disturb the depth that was selected by the three-point hitch control lever. When switch (28) is released, the three-point hitch will return to the depth that was set by the three-point hitch control lever.
Draft/position control knob (5) adjusts the sensitivity of the optional electronic draft control. Rotate the knob fully in the counterclockwise direction in order to operate the hitch in the position control detent. Rotate the knob fully in the clockwise direction in order to operate the hitch in the most sensitive setting. The hydraulic system will respond to changes in draft load with large movements of the implement. Turning the knob in the counterclockwise direction will progressively decrease the amount of linkage movement that is relative to changes in the draft load. The rate of linkage movement will also decrease.
Observe the implement while you pull the implement through the ground. If the reaction of the hydraulic system is too great, reduce the sensitivity. Turn the draft/position control knob in the counterclockwise direction in order to reduce the sensitivity. Continue this process until the amount of implement movement is acceptable.
Note: When you are working near the three-point hitch, always set draft/position control knob (5) to position "1". This will prevent movement of the three-point hitch.
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| Illustration 4 | g00636551 |
Note: If the machine is equipped with a slip limit override control, the machine must also be equipped with a ground speed sensor.
The ground speed sensor is powered by voltage from the Electronic Monitoring Center. The ground speed sensor emits a high frequency output that bounces off the ground under the machine. This signal is reflected back to the ground speed sensor. Next, the signal is converted to an alternating current that is sent to the Electronic Monitoring Center. The high frequency output increases as the ground speed of the machine increases.
Slip limit override control (30) and lamp (29) are installed in the right hand console. Slip limit override control (30) is a variable potentiometer that is connected to the Right Hand Control Module and to the Chassis Control Module. The control modules calculate the difference between the true ground speed from the ground speed sensor and the ground speed from the transmission speed sensor. This difference is the percentage of track slippage.
Slip limit override control (30) allows the operator to vary the depth of an implement if the track slippage exceeds a certain percent. The depth of the implement can be varied manually or the depth of the implement can be varied automatically. Slip limit override control (30) and lamp (29) are located on the right hand console. This feature allows the operator to select a limit for track slippage. If this percentage is exceeded, the electronic draft control is overridden. When the selected track slippage has been exceeded, the three-point hitch will raise until the track slippage falls below the preset value. Once the track slippage is reduced, the three-point hitch will return to the depth that was originally selected by the three-point hitch control lever.
Lamp (29) is illuminated whenever the percentage of track slippage exceeds the selected limit. The slip limit override control can be turned off by rotating control (30) fully in the clockwise direction to the detented OFF position. The limit for track slippage can be set in the range of 8 to 20 percent. Rotate control (30) in the counterclockwise direction in order to select the limit of track slippage. The dashes on the decal represent increments of three percent. A digital display of the track slippage may be viewed on the Machine Performance Monitor. See Operation and Maintenance Manual, "Electronic Monitoring Center" for more information.
If the machine is equipped with electronic draft control, the slip limit override control will work when the draft/position control knob is in the position control detent.
Note: The slip limit override control will not operate below a ground speed of 0.8 km/h (0.5 mph).
Note: The slip limit override control will deactivate when the three-point hitch is raised with the three-point hitch raise/lower switch or the three-point hitch control lever. The slip limit override control will activate once the three-point hitch is lowered and a significant draft load is produced.
Three-point hitch status display (4) serves two purposes. When three-point hitch status display (4) is flashing, a malfunction in the three-point hitch has been recognized. If three-point hitch status display (4) is illuminated consistently, the three-point hitch has been disabled. The hitch disable symbol is displayed on the Machine Performance Monitor (MPM) as an LCD readout. The hitch disable symbol and three-point hitch status display (4) are activated when any of the following conditions occur:
- The three-point hitch is placed in the external operating zone.
- The machine is started with three-point hitch raise/lower switch (1) in the RAISE position.
- The three-point hitch control lever (3) is moved while the engine is stopped.
- The three-point hitch linkage has changed positions while the engine is stopped.
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| Illustration 5 | g00479257 |
External position control switch (8) External position control switch | |
External position control switch (8) is provided in order to assist the operator in attaching an implement. Switches (8) are located on the rear of the fenders. When the switches are released, the switches return to the OFF position.
The following conditions must exist in order to activate the external position control switches:
- The parking brake is applied.
- The transmission control lever is in the NEUTRAL position.
- The PTO is disengaged.
- The engine is at low idle.
Note: The status light for the three-point hitch and the hitch disable symbol will be displayed when you activate the external position control switch.
In order to use the switch, stand at the side of the machine while you press and while you hold the top part of the switch in order to raise the hitch. Press and hold the bottom area of the switch in order to lower the three-point hitch.
Note: Operation of the switches will cause the three-point hitch to move at a slower rate.
In order to transfer the control of the three-point hitch back to the three-point hitch control lever, use the following procedure.
- Toggle the three-point hitch raise/lower switch to the LOWER position. If the switch is already in the LOWER position, toggle the switch to the RAISE position and back to the LOWER position.
- Move the three-point hitch control lever slowly in the rearward direction in order to capture the three-point hitch. If necessary, move the three-point hitch control lever slowly in the forward direction in order to capture the three-point hitch. The hitch enabled symbol will be displayed on the Machine Performance Monitor. The status light for the three-point hitch will be turned off. The three-point hitch linkage is now phased with the three-point hitch control lever.
The following items send signals to the Right Hand Control Module: three-point hitch control lever, switches and knobs. The Right Hand Control Module communicates with both the Electronic Monitoring Center and the Chassis Control Module. The control modules send a pulse width modulated signal that is DC current to the two solenoids on the three-point hitch control valve.
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| Illustration 6 | g00479256 |
(9) Machine Performance Monitor (MPM) (10) Fault code indicator (11) Hitch disabled symbol (12) Hitch position (13) Hitch enabled symbol | |
The Machine Performance Monitor (MPM) (9) automatically displays the following information for the three-point hitch.
Hitch enabled symbol (13) indicates that the three-point hitch is phased with the three-point hitch control lever.
A value (12) between 0 and 99 is displayed in order to indicate the relative position of the three-point hitch. A zero reading indicates a fully lowered three-point hitch. A reading of 99 indicates a three-point hitch that is fully raised.
Hitch disabled symbol (11) indicates that the three-point hitch is out-of-phase with the three-point hitch control lever.
The symbol for fault code indicator (10) indicates that an electrical fault has been detected.
Note: See Systems Operation/Testing and Adjusting, RENR1781 for more information about the fault codes for the three-point hitch.
Component Location
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| Illustration 7 | g00509662 |
Three-point hitch with quick hitch (14) Top link (15) Lift arm (16) Adjustment lever (17) Hook for storing the center link (18) Floating pin (19) Three-point hitch rockshaft (20) Potentiometer (21) Three-point hitch lift cylinder (22) Lift link (23) Handle assembly (24) Draft sensor pin (25) Draft arm (26) Sway limiter (27) Quick hitch | |
Lift arms (15) pivot on three-point hitch rockshaft (19). Three-point hitch rockshaft (19) is located on top of the rear axle housing.
Lift arms (15) have seals at each end. The seals are installed so that the sealing lip faces inward. Three-point hitch lift cylinders (21) are attached to lift arms (15) .
Feedback potentiometer (20) provides the Chassis Control Module (CCM) with a signal. The signal shows the relative position of lift arms (15) .
The standard three-point hitch lift cylinders provide a lift capacity of 5669 kg (12,500 lb). Three-point hitch lift cylinders with a larger diameter are available in order to provide a lift capacity of 6802 kg (15,000 lb).
Note: The lift capacity of the three-point hitch is rated at 610 mm (24 inch) behind the ball ends.
Both sizes of three-point hitch lift cylinders have the same stroke. The three-point hitch lift cylinders are installed with the rod end in the upward direction.
Sway blocks and spacers are mounted on the inside of draft arms (25). The sway blocks ride on sway limiter (26). This controls the width that is between draft arms (25) .
Remove the spacers that are between the sway blocks and draft arms (25) in order to change the three-point hitch from Category III to Category IIIN.
The available Category III quick hitch (27) provides a fast, easy method for attaching and for removing three-point hitch implements. The quick hitch can be converted to category IIIN. Quick hitch (27) moves the lower lifting points to the rear approximately 127 mm (5 inch). The lift capacity is slightly reduced. This is due to the change in the mechanical advantage.
Draft sensor pins (24) are installed on the front pivot point of draft arms (25). Machines that are not equipped with electronic draft control do not have draft sensor pins (24) .
Draft sensor pins (24) provide a change in electrical resistance as distortion occurs from the draft load that is applied.
The CCM measures the change in electrical resistance. The CCM will adjust the position of the draft arms in order to maintain the setting of the draft/position control knob.
Draft sensor pins (24) are designed and installed in order to sense the draft from the horizontal position. Draft sensor pins (24) do not sense the vertical weight of a mounted implement.