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John Deere 3120, 3320, 3520, 3720 - Hydraulic and Hitch

John Deere 3120, 3320, 3520, 3720 Three Point Hitch

Drawbar Hitch

Maximum static vertical load on drawbar should not exceed the maximum recommendations. Drive slowly with heavy loads. Maximum Drawbar Loads - Certain heavy equipment such as a loaded single-axle trailer can place excessive strain on the drawbar. Strain is greatly increased by speed and rough ground. Adjusting Drawbar Length - For drawn PTO-driven implements, the drawbar must be in the operating position. The JD 3120, 3320, 3520, 3720 drawbar is equipped with two adjusting holes for changing drawbar length and one hole for storage. Remove quick-lock pin and drilled pin. Adjust drawbar to operating position, or to storage position. Install drilled pin up from bottom of machine. Secure with quick-lock pin.

3 Point Hitch

The 3-point hitch on John Deere 3120, 3320, 3520, 3720 tractor is classified as a Category 1 hitch. Place center link in storage hook when the hitch is not in use. Positioning Center Link - For light and medium draft loads: Install center link in bottom hole of mounting bracket. Example of light and medium draft load implements would include a landscape rake. For medium and heavy draft loads: Install center link in middle hole of mounting bracket. Example of medium and heavy draft load implements would include a tiller or box blade. For very heavy draft loads: Install center link in top hole of mounting bracket. Example of very heavy draft load implements would include a plow or ripper.

Using Rockshaft Control Lever

Use rockshaft control lever to raise and lower equipment attached to the 3-point hitch. The six calibrated setting are for reference only and do not signify specific operating depths. When the rockshaft control lever is moved forward, the draft arms will lower closer to the ground. Lower Implement: Push rockshaft control lever forward. Raise Implement: Pull rockshaft control lever rearward. The adjustable depth stop can be adjusted to maintain a particular implement operating depth. To use the depth stop knob: Operate implement for a few minutes to determine the desired operating depth. Loosen the depth stop knob. Move knob against rockshaft control lever. Tighten knob to keep the depth stop in position. Implement will operate in same position each time rockshaft control lever is pushed against the depth stop.

Using Rate of Drop/Lock Valve

To prevent overheating hydraulic oil and damaging machine, do not raise rockshaft when drop/lock valve is closed. The rate of drop/lock valve controls the rate of rockshaft drop when the rockshaft control lever is operated. This provides direct rate of drop control for 3-point hitch mounted implements. The valve can also be used to hydraulically lock the rockshaft (three-point hitch) in a desired position. Increase Rate of Drop: Rotate drop/lock valve knob counter-clockwise to make drop faster. Decrease Rate of Drop: Rotate drop/lock valve knob clockwise to make drop slower. Loss of hydraulic pressure could result in sudden drop of attachment. Lower attachment onto blocks or remove from machine before servicing. Lock 3-Point Hitch: Rotate drop/lock valve knob clockwise until tight. Unlock 3-Point Hitch: Rotate drop/lock valve knob counter-clockwise.

Using Draft Links

Slowly back machine into position to align draft links with implement lift brackets. Park machine safely. For John Deere 3120, 3320, 3520, 3720 tractor equipped with optional telescoping draft links: Raise locking lever and pull link to extend as needed. Connect draft links to the implement. Telescoping draft link locking levers must be in locked position before operating the machine or link damage could occur. For machines equipped with optional telescoping draft links: Sit on operator’s seat and start engine. Back machine until each lock lever snaps and secures each draft link in the locked position.

John Deere 3120, 3320, 3520, 3720 Implements

Leveling Implement Front-to-Rear

Leveling a 3-point hitch mounted implement front-to-rear is accomplished by adjusting the length of the center link. Loosen locknut. Do not turn center link body past the stops, or threads may be damaged. Rotate handle to lengthen or shorten the center link. Tighten locknut. Leveling Implement Side-to-Side - Use turn handle on the right adjustable lift link to level a 3-point hitch implement side-to-side. Raise lift link turn handle from transport position and locking tab. Rotate handle approximately 1/2 turn. Lower handle notch onto roll pin. Rotate handle to raise or lower draft link until 3-point hitch mounted implement is level from side-to-side. Return handle to the transport position with handle notch on locking tab.

Adjusting Implement Side-to-Side Sway

Check implement operator’s manual procedure for adjusting sway links. When sway links have been properly adjusted, side sway of implement is controlled by position of links. Use left and right sway links to adjust 3-point hitch implement side-to-side sway. Remove locking pin. Slide links to adjust length. Install locking pin. Adjusting Draft Links to Float Position - Adjusting 3-point hitch stops to the float position will allow both draft links to raise slightly as the implement follows ground contour. Adjust stops to the float position for 3-point hitch implements such as a cultivator or mower. These implements will have ground gauging skids or wheels which may otherwise cause the implement to twist relative to the machine. Carefully remove spring locking pin, drilled pin and stop connecting each draft link and lift link. Connect each lift link and draft link with the same hardware, making sure the stop is installed in the same position shown.

Adjusting Draft Links to Rigid Position

Adjusting 3-point hitch stops to the rigid position will restrict movement of the draft links as the implement follows ground contour. Adjust stops to the rigid position for 3-point hitch implements such as plows and ground engaging implements that should not twist relative to the machine. Carefully remove spring locking pin, drilled pin and stop connecting each draft link and lift link. Connect each lift link and draft link with the same hardware, making sure the stop is installed in the same position.

John Deere 3120, 3320, 3520, 3720 Tractor iMatch Quick-Hitch

John Deere 3120, 3320, 3520, 3720 tractor Installing Hitch - Remove three drilled pins and two bushings from hitch. Use machine rockshaft control lever to fully lower 3-point hitch draft links. Park machine safely. Position hitch near draft links and adjust 3-point hitch sway links to align draft links with hitch. Install hitch on draft links using drilled pins. Install 3-point hitch center link on hitch using center link quick-lock pin and drilled pin. Connecting Implement - Install two bushings included with hitch on drilled pins in implement draft link lift brackets. Move levers on hitch to unlocked position. Back machine into position and align hitch with implement lift brackets. Use rockshaft control lever to position hitch under lift brackets and lift implement from ground. Fully raise implement. Move levers on hitch to locked position.

John Deere 3120, 3320, 3520, 3720 Tractor - Removing Implement and Hitch

With implement in raised position, move levers to unlocked position, then lower implement to ground. Move tractor forward to disengage hitch from implement. Move levers on hitch to locked position. Use machine rockshaft control lever to fully lower hitch and 3-point draft links. Remove drilled pins from 3-point hitch center link and draft links. Place drilled pins in hitch for storage. Move John Deere 3120, 3320, 3520, 3720 tractor forward to disengage from hitch. Connecting Implement Hydraulic Hoses - Relieve hydraulic pressure: Move dual selective control valve (SCV) lever rearward-to-forward and side-to-side several times. Move third SCV lever rearward-to-forward several times if equipped. See your implement operator’s manual for specific instructions on connecting hydraulic hoses to couplers. Install hose ends in couplers with matching colors. Colors for the couplers are shown on the label installed on the machine near the couplers. See your implement operator’s manual for specific instructions on operating SCV controls. To prevent contamination of female quick couplers, color-coded hose ends should be installed in the couplers when not being used.

Dual Selective Control Valve Lever

The label installed on the machine next to the dual selective control valve (SCV) lever shows the different lever positions. Lever positions numbered 1-4 on the label match hydraulic line couplers numbered 1-4 on the label installed on the machine near the couplers. Moving the lever to position 1 will supply fluid to coupler 1 and return fluid through coupler 2 and so forth. Move the lever to the full right or regen position for faster loader bucket dumping. Move the lever to the full forward or float position to remove pressure in both lines 3 and 4 and allow fluid to flow back and forth between the lines. The lever may be left in the float position.

Dual Selective Control Valve (SCV) Lock Lever

John Deere 3120, 3320, 3520, 3720 Tractor without Cab - Selective Control Valve (SCV) lock lever allows the operator to control the type of dual SCV lever movement needed for a particular operation or situation. Operation of the lock lever is indicated on label. To allow movement of dual SCV lever in all directions, move lock lever to the top position. Operation of the dual SCV is totally unlocked. To prohibit engagement of the regen (regeneration) function of the dual SCV, move lock lever to the middle position. This position is recommended for all implements except for the front loader. Heavily-loaded loader buckets will dump more rapidly when the regen function is engaged. The regen function is available only with the lock lever in position C. To prohibit movement of dual SCV lever in all directions, move lock lever to the bottom position. Operation of the dual SCV is totally locked.

JD 3120, 3320, 3520, 3720 Tractor with Cab - Selective Control Valve (SCV) lock lever allows the operator to control the type of dual SCV lever movement needed for a particular operation or situation. Operation of the lock lever is indicated on label. To allow movement of dual SCV lever in all directions, push the lock lever inward to center position. Operation of the dual SCV is totally unlocked. To prohibit engagement of the regen (regeneration) function of the dual SCV, push the lock lever all the way inward. This position is recommended for all implements except for the front loader. Heavily-loaded loader buckets will dump more rapidly when the regen function is engaged. To prohibit movement of dual SCV lever in all directions, make sure SCV lever is in center position, and pull the lock lever straight outward. Operation of the dual SCV is totally locked. After extended use, the dual SCV lever may require cable adjustment to lock out.

Hydraulic Third Selective Control Valve (SCV)

John Deere 3120, 3320, 3520, 3720 tractor can be equipped with an optional hydraulic third Selective Control Valve (SCV) and hydraulic outlets to operate hydraulically-driven implements. The machine-mounted hydraulic outlets are female quick couplers (A). When the implement hydraulic hoses are connected to the couplers, move the third SCV lever forward to divert fluid to the lower connector line and return through the upper connector line. Move the lever rearward to divert fluid to the upper connector line and return through the lower connector line. Move the lever to the full forward or float position to remove pressure in both connector lines and allow fluid to flow back and forth between the lines. See your implement Operator’s Manual for implement functions which correspond to lever positions. To prevent contamination of female quick couplers, color-coded hose ends should be installed in the couplers when not being used.

John Deere 3120, 3320, 3520, 3720 Diverter Valve

JD 3120, 3320, 3520, 3720 models can be equipped with an optional diverter valve and hydraulic outlets to operate hydraulically-driven implements. The machine-mounted hydraulic outlets are female quick couplers. If the key switch is moved to the off position, the dual SCV lever will default to operating the front quick couplers. The key switch must be moved to the run position and the diverter system re-activated to operate the rear couplers. Press the front of the diverter switch to activate the rear SCV quick coupler ports. The switch indicator light will go on. Press the back of the diverter switch to deactivate the rear SCV quick coupler ports. The switch indicator light will go off.