Specifications, Service and Repair of Farm and Lawn Tractors

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John Deere 5620, 5720, 5820 Hydraulics and Hitch

JD 5620, 5720, 5820 Hydraulic System

Selective Control Valves

The 5620, 5720, 5820 John Deere tractor may be equipped one of three different types of selective control valve: 105 Series, 205 Series or 305 Series. 105 Series selective control valves provide the functions "Raise", "Neutral" and "Lower". 205 and 305 Series selective control valves provide an additional "Float" position.

Series 305 selective control valves also offer the following choices:

- The control lever remains in the "Raise" or "Lower" position until it is moved manually.
- The control lever moves to "neutral" as soon as it is released.
- The control lever remains in the "Raise" or "Lower" position until the pressure in the oil circuit has reached a predetermined value (e.g. when the remote control cylinder has reached its end position).

Levers for Selective Control Valves



A - Retract, B - Extend, C - Neutral position, D - Float position

- The control lever has four settings. The remote cylinder retracts when the lever is moved to the "Retract" position.
- The remote cylinder extends when the lever is moved to the "Extend" position. The remote cylinder is held in place when the lever is in "Neutral".
- When the lever is in the "Float" position (i.e. piston moves freely inside remote cylinder), the mounted implement follows the ground contours.
- If additional external valves are used, move the control lever to neutral when shutting off each hydraulic function.
- Locks (A) allow the control levers to be secured in neutral.
- Apply locks (A) when driving on roads and whenever the control levers are in neutral because they are not required.

Multi-Function Lever



A - Multi-function lever, B - Buttons for additional functions, C - Transport lock slide control, D - Upshift/downshift buttons

- Multi-function lever (A) permits two SCVs to be operated at the same time. Buttons (B) allow additional functions to be performed.
- The slide control (C) can be used to lock the lever.
- The multi-function lever must be locked when the John Deere 5620, 5720, 5820 tractor is driven on proper roads.
- If upshift/downshift buttons (D) are equipped, they allow the gears at the transmission to be shifted.

Rate of Cylinder Operation - The flow control valve can be used to adjust rate at which the rockshaft rises and drops (with 305 Series selective control valves only). Full extension and retraction of a remote cylinder should require at least 1.5 seconds. Faster speeds may cause damage.

Remote Hydraulic Cylinder - The total retract stroke may be varied from 0 to 203 mm (0-8 in.) by means of the adjustable stop. Turn adjustable stop so that stop rod arm does not come into contact with stop lever. After the adjustable stop comes into contact with the stop rod arm, a further 38 mm (1.5 in.) of slow travel is gained if remote cylinder control lever is held in "retract" position.

Changing Hydraulic Oil

- Start engine and operate several hydraulic functions to heat up oil.
- Park JD 5620, 5720, 5820 tractor so that it is level. Lower draft links and front-mounted implements.
- Shut off engine and remove key. Apply the parking brake (Transmission in neutral).
- Remove drain screws (A). Replace hydraulic oil filter elements (B).
- At the left side of the tractor underneath the rear axle, take out plug (C), remove the intake screen and wash it in fuel.
- Before refilling with fresh oil, reinstall intake screen, replace seals and tighten drain screws to 50 N·m (35 lb-ft).
- Add hydraulic oil to the transmission case.

Front Three-Point Hitch

This three-point hitch can be operated with SCV I.

Multi-valve

The additional multi-valve allows the following settings:

- Oil flow blocked.
- Raising with oil pressure, lowering with deadweight of implement.
- Raising and lowering with oil pressure.

If SCV I is equipped with additional couplers towards the rear (for operation of rear implements), the multi-valve must be blocked before rear implements are operated using SCV I. When a chain is used to limit the cutting height on a mowing unit, avoid damage by selecting setting. Additionally, set SCV I to float position to lower the mowing unit.

Couplers

Oil pressure is available at coupler when the hitch is raised. Couplers are provided with oil via SCV II or III.

The couplers allow the hydraulic hose to be connected and disconnected only if no pressure is present. For coupler this means that the front hitch must be lowered. To connect the hose union, press it firmly into the coupler. To disconnect the hose, give it a firm pull.

Brackets for mowing unit suspension (if equipped) - Opening allows attachment of the chain for cutting height limit. In this case, avoid damage by selecting setting for the multi-valve. Additionally, set SCV I to float position to lower the mowing unit. Bore allows attachment of the suspension spring.

Hydraulic System Troubleshooting

Hydraulic system fails to function Not enough oil in the system Top up to mark on dipstick.

Hydraulic oil overheats Clogged hydraulic filters Replace hydraulic filters.
Dirt in hydraulic pump Check filter for clogging.
Oil cooler air passages clogged Clean oil cooler.
Dirt in hydraulic pump Check filter for clogging.

Hitch fails to lift load Excessive load on hitch Adjust auxiliary springs on implement or reduce load.

Hitch drops too slowly Rate-of-drop regulator not adjusted properly Adjust rate of drop.

No hitch response to draft load System regulator in Height or Load-and-Depth Control position Place system regulator in Load Control position.

Hitch too active System regulator in Load Control position Place system regulator in Load-and-Depth position.

Direction of remote cylinder travel is reversed Hoses connected incorrectly Connect hoses correctly.

Remote cylinder will not lift load Excessive load Adjust auxiliary springs on implement or reduce load.
Hoses on quick-coupler not correctly attached Attach hoses to quick-coupler correctly.
Air in remote cylinder Bleed cylinder.

Remote cylinder travels too fast or too slowly Rate-of-lift is adjusted incorrectly Adjust rate of lift.

John Deere 5620, 5720, 5820 Hitch and Drawbar

Hitch Dampening

The 5620, 5720, 5820 John Deere tractor is equipped with a hitch dampening function that prevents the tractor from "pitching" when it is travelling with a raised implement. To activate the dampening function, first move hitch control lever (A) (with the engine running) to the position that corresponds to the position of the draft links.

Then pull it as far as it will go to the rear (beyond "0") to the transport position (see arrow). The rate-of-drop control must NOT be in the left-hand end position. To switch off the dampening function, push the hitch control lever forward from the transport position to a position beyond "0" (in the "drop" direction).

Adjustable Drawbar

The drawbar is used to pull drawn equipment of all types, particularly PTO-driven implements. The drawbar hitch is located so as to increase the rear axle load and at the same time slightly reduce load on the front axle. Besides having a variable swinging range, the drawbar can also be adjusted lengthwise. Maximum permissible static vertical loads and towable drawbar loads are stated in the Specifications. Towing on public roads with the swinging drawbar set to one side is not permitted!



A - Hex Plug, B - Locking pin, C - Drawbar

The drawbar can be adjusted to three different lengths: 250 mm (9.8 in.), 350 mm (13.8 in.) and 400 mm (15.7 in.). These lengths determine the distance from the end of the PTO shaft to the attachment point of the drawbar.

- Remove hex plug (A).
- Remove locking pin (B).
- Adjust drawbar (C) and reinstall locking pin.
- Tighten hex plug (A) to 310 Nm (225 lb-ft).

Height-Adjustable Trailer Hitch

- The JD 5620, 5720, 5820 tractor can be equipped with different hitch versions which are operated in different ways.
- The height of all hitches can be adjusted using lever. On hitch the hitch pin is operated using handle.
- Hitches can be opened and closed by means of lever. Hitches can also be closed by inserting the trailer towing eye.
- Use only trailer hitches with a towing eye diameter of 40 mm (137 / 64 in.).
- Trailer hitches with different dimensions may be available in certain countries.

Pick-Up Hitch

This type of hitch can be operated via the rockshaft and one selective control valve.

- Connect hydraulic hoses to the quick-couplers. Raise draft links to maximum height and use SCV to retract the hitch hook fully.
- Pull release lever and hold it until the hitch hook has moved from the stored position (lever remains in "open" position).
- Extend the hitch hook fully by actuating the selective control valve. Lower draft links/hitch hook to desired height.
- Raise draft links to engage hitch hook in trailer towing eye, then continue to raise the hitch fully.
- Retract the hitch hook fully by means of selective control valve until it is fully locked (lever returns to its starting position).
- Lower the draft links. Check that the hitch is locked correctly.
- It will not lower when the draft links are lowered and not extend when the selective control valve is operated.
- Hook of pick-up hitch can be replaced by a drawbar without the use of tools. To do so, lift out pin.

Rockshaft Control

The rockshaft is controlled by means of hitch control lever and raise/lower switch. The lift height can be limited by means of the height-limit control.

To make the rockshaft ready for operation, start the engine and either:

- Move control lever to the position that corresponds to the position of draft links.
- Move control lever to one of the end positions, or actuate raise/lower switch.
- Pull control towards "0" - raise implement.
- Push control towards "9" - lower implement.

The implement can be raised and lowered independently of control lever by means of raise/lower switch. This is of assistance when turning at the end of a field, for example. If the upper part of the raise/lower switch is pressed, the implement is raised as high as the setting at height-limit control. If the lower part of the raise/lower switch is pressed, the implement is lowered as far as the setting at control lever. To obtain working depth more quickly in compact soil at the headland (quick lower), keep raise/lower switch pressed. As long as raise/lower switch is pressed, the adjusted draft force is not active (override function). If raise/lower switch is released, the implement returns to the previous settings.

This "quick lower" function will only work if:

- The implement has been raised using switch.
- The implement is lowered continuously from raised position using switch.
- Pull control lever as far as it will go (beyond "0") - rockshaft is locked.

Headland Management System HMS II (If Equipped) - Basic Principles

HMS II makes it possible to record and save sequences of functions that occur repeatedly and to call them up as programs when needed (tape recorder principle). Two such programs can be stored at any one time. Each of them can include up to 20 functions. The programs remain in the memory until they are deleted, even if the electrical current is switched off.

Recordings may be made of the functions of the following tractor sub-assemblies: differential lock, rockshaft, rear PTO, front PTO and front-wheel drive. The distance the tractor moves between functions is also stored. The recording is therefore not dependent on the tractor's speed.

Sample programming (end/start of field)

Initial situation: JD 5620, 5720, 5820 tractor operating in field, rear implement is lowered, front-wheel drive is on, rear PTO is on.

- Press HMS II on/off switch - Acoustic signal, HMS II indicator light comes on.
- Press Record/save switch - Acoustic signal every 2 seconds, light flashes.
- Press Program switch to "1" or "2" - Indicator Light or flashes.
- Raise rear implement - The tractor must be driven at a speed of at least 0.5 km/h (0.31 mph).
- Switch off rear PTO - The tractor must be driven at a speed of at least 0.5 km/h (0.31 mph).
- Switch off front-wheel drive - This step may be performed with the tractor stationary (clutch depressed).
- Press switch Record/save - Light goes out, HMS II indicator light remains on continuously (not flashing).

Initial situation: John Deere 5620, 5720, 5820 tractor is at the headland, rear implement is raised, front-wheel drive is off, rear PTO is off.

- Press Record/save switch - Acoustic signal every 2 seconds, HMS II indicator light flashes.
- Press Program switch to "1" or "2" - Program 1 indicator Light or Program 2 indicator flashes.
- Lower rear implement - The tractor must be driven forward at a speed of at least 0.5 km/h (0.31 mph).
- Switch on rear PTO - The tractor must be driven forward at a speed of at least 0.5 km/h (0.31 mph).
- Switch on front-wheel drive - This step may be performed with the tractor stationary (clutch depressed).
- Press Record/save switch - Light goes out, light remains on continuously (not flashing).
- Press HMS II on/off switch - Acoustic signal, light goes out.

Performing the stored programs

To enable the recorded programs to be performed, the 5620, 5720, 5820 John Deere tractor must be driven at a speed of at least 0.5 km/h (0.31 mph). Before programs are performed that include front-wheel drive and/or PTO functions, front-wheel drive and/or the PTO(s) must be switched on. HMS II cannot physically "turn on" the relevant switches. Before programs are performed that include rockshaft functions, the relevant lever must be in neutral position.

1. Pressing on/off switch makes HMS II indicator light come on.
2. To select the desired program, press program switch to "1" or "2".
Program indicator light will come on. This light goes out once the program has been completed.

Headland Management System HMS II - Details

Basic controls

On/off switch:

When this switch is actuated, an acoustic signal is emitted.

- If this switch is actuated while the HMS II mode is on, it turns the HMS II mode off.
- Actuating this switch does not activate the HMS II mode unless program switch is in its neutral position.
- If this switch is actuated while a program is being recorded, the recording of the program is interrupted and the program does not get stored in the memory.
- If this switch is actuated while a program is being performed, the program stops.

Record/save switch:

When this switch is actuated, an acoustic signal is emitted.

- If this switch is actuated while the HMS II mode is off, it has no effect.
- If this switch is actuated while the HMS II mode is on, it starts to record a program.
- If this switch is actuated while a program is being recorded, the relevant program (1 or 2) is stored in the memory.

Program switch:

- If this switch is actuated while the HMS II mode is off, it has no effect.
- If this switch is actuated while the HMS II mode is on, the relevant program (1 or 2) will start.
- If this switch is actuated while a program is being recorded, the following functions are allocated to the relevant program.

Differential lock: The "on"/"off" status is recorded.

Front-wheel drive: The status "brake assist (off)", "on" and "auto" is recorded. If HMS II is to perform a program that includes a front-wheel drive function, the FWD switch must be either in the "on" position or the "Auto" position. If HMS II switches FWD off, the FWD indicator light will flash "slowly" (on briefly, off for longer) until HMS II switches FWD on again or until the FWD switch is moved to its "off" position. In the event of HMS II being switched off during the period of slow flashing, the FWD indicator light changes to "rapid" flashing (on/off for the same length of time) until the FWD switch is moved to its "off" position.

Rear PTO: The "on"/"off" status is recorded. If HMS II is to perform a program that includes a PTO function, the PTO switch must be in its "on" position. If HMS II switches the PTO off, the PTO indicator light will flash "slowly" (on briefly, off for longer) until HMS II switches PTO on again or until the PTO switch is moved to its "off" position. In the event of HMS II being switched off during the period of slow flashing, the PTO indicator light changes to "rapid" flashing (on/off for the same length of time) until the PTO switch is moved to its "off" position.

Front PTO: The "on"/"off" status is recorded. If HMS II is to perform a program that includes a PTO function, the PTO switch must be in its "on" position. If HMS II switches the PTO off, the PTO indicator light will flash "slowly" (on briefly, off for longer) until HMS II switches PTO on again or until the PTO switch is moved to its "off" position. In the event of HMS II being switched off during the period of slow flashing, the PTO indicator light changes to "rapid" flashing (on/off for the same length of time) until the PTO switch is moved to its "off" position.

Rockshaft: The "raise", "lower" and "quick lower" functions are recorded. If HMS II is to perform a program that includes a rockshaft function, the rockshaft control switch must be in its neutral position.

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