Service Engine - Model GX345

Maintenance, repair, or replacement of the emission control devices and systems on this engine, which are being done at the customers expense, may be performed by any non-road engine repair establishment or individual. Warranty repairs must be performed by an authorized John Deere dealer.

Avoid Fumes

c CAUTION: Avoid injury! Engine exhaust fumes contain carbon monoxide and can cause serious illness or death.

Move the vehicle to an outside area before running the engine.

Do not run an engine in an enclosed area without adequate ventilation.

· Connect a pipe extension to the engine exhaust pipe to direct the exhaust fumes out of the area.

· Allow fresh outside air into the work area to clear the exhaust fumes out.

Engine Oil

Use oil viscosity based on the expected air temperature range during the period between oil changes.

The following John Deere oils are preferred:

MX4888

· TURF-GARD®

· PLUS-4®

Other oils may be used if above John Deere oils are not available, provided they meet the following specification:

· API Service Classification SG or higher

Checking Engine Oil Level


IMPORTANT: Avoid damage! Failure to check the oil level regularly could lead to serious engine problems if oil level is low: · Check oil level before operating. · Check oil level when the engine is cold and not running. · Keep level between the FULL and the ADD marks. · Shut off engine before adding oil.

NOTE: Check oil twice a day if you run engine over 4 hours in a day.

Make sure engine is cold when checking engine oil level.

1. Park machine safely. (See Parking Safely in the SAFETY section.)

2. Lift hood.

3. Clean area around dipstick to prevent debris from falling into crankcase.

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4. Remove dipstick (A). Wipe with clean cloth.

5. Install dipstick into tube, but do not tighten it. Let dipstick threads rest on top of tube.

6. Remove dipstick.

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7. Check oil level on dipstick. Oil must be between ADD and FULL marks (B).

8. If oil level is low, add oil to bring oil level no higher than FULL mark on dipstick.

9. Install and tighten dipstick. Lower hood.

Changing Engine Oil and Filter

1. Run engine to warm oil.

2. Park machine safely. (See Parking Safely in the SAFETY section.)

3. Raise hood.

4. Put drain pan under drain valve. If available, install drain hose.

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5. Open drain valve (A) and drain oil into drain pan. Allow oil to drain completely.

6. Remove dipstick (B).

7. Wipe dirt from around oil filter (C).

8. Place a drain pan or funnel under filter tray.

9. Remove old filter and wipe off filter tray.

10. Put a light coat of fresh, clean oil on the filter gasket.

11. Install replacement oil filter by turning oil filter to the right (clockwise) until the rubber gasket contacts filter base. Tighten filter an additional one-half turn.

12. Close drain valve.

13. Add oil:

· With oil filter change: 1.9 L (2.0 qt)

· Without oil filter change: 1.7 L (1.8 qt)

14. Install and tighten dipstick.

15. Start and run engine at idle to check for leaks. Stop engine. Fix any leaks before operating.

16. Check oil level, add oil if necessary.

Cleaning Air Intake Screen


IMPORTANT: Avoid damage! The engine requires a large amount of air intake when running. Reduced air intake can cause overheating: · Keep air intake screen clean. · Keep covers and screens in place.

1. Park machine safely. (See Parking Safely in the SAFETY section.)

2. Raise hood.

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3. Clean engine screen (A) and external surfaces of engine with rag, brush, vacuum or compressed air.

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· When operating in extremely dirty conditions, remove air intake screen and clean radiator screen (B).

4. Lower hood.

Servicing Air Cleaner Elements

1. Park machine safely. (See Parking Safely in the SAFETY section.)

c CAUTION: Avoid injury! Touching hot surfaces can burn skin. The engine and components will be hot if the engine has been running. Allow the engine to cool before servicing.

2. Allow engine to cool.

3. Remove hood.

4. Remove air intake screen.

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5. Remove wing nuts (A), washers, and filter housing (B).


IMPORTANT: Avoid damage! Dirt and debris can enter the engine through a damaged filter element: · Do not wash paper element. · Do not attempt to clean paper element by tapping against another object. · Do not use pressurized air to clean element. · Replace element only if it is very dirty, damaged or the seal is cracked.

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6. If precleaner (C) is dirty, carefully remove paper element and precleaner. Remove precleaner from element (D).

7. If paper element is excessively dirty, replace it with a new element.

8. If precleaner is damaged, replace it. If precleaner is dirty, clean it as follows:

a. Wash it in a solution of warm water and liquid detergent. Do not wash paper element.

b. Rinse precleaner.

c. Squeeze excess water from precleaner.

d. Allow precleaner to air dry.

e. Add approximately 30 ml (1 oz) of clean engine oil to precleaner.

f. Squeeze precleaner to distribute oil evenly.

9. Install precleaner on paper element and install air cleaner.

10. Install air cleaner cover and wing nuts.

11. Install hood.

Recommended Engine Coolant

The following John Deere coolant is preferred:

· COOL-GARD PRE-DILUTED SUMMER COOLANT (TY16036).

· COOL-GARD CONCENTRATED SUMMER COOLANT (TY16034)

If neither of the above coolants is available, use an ethylene glycol base coolant that meets the following specification:

· ASTM D4985 (JDM H24A2)

Check container label before using to be sure it has the appropriate specifications for your machine. Use coolant with conditioner or add conditioner to coolant before using.

If using concentrate, mix approximately 50 percent antifreeze with 50 percent distilled or deionized water before adding to cooling system. This mixture will provide freeze protection to -37 degrees C (-34 degrees F).

Certain geographical areas may require lower temperature protection. See the label on your antifreeze container or consult your John Deere dealer to obtain the latest information and recommendations.

Checking Coolant Level


IMPORTANT: Avoid damage! Using incorrect coolant mixture can damage the radiator: · Do not operate engine without coolant or with plain water. · Use antifreeze approved for use in aluminum engines. · Do not exceed a 50% antifreeze mixture for the coolant. · Do not pour coolant or water into radiator when engine is hot.

1. Park machine safely on a level surface. (See Parking Safely in the SAFETY section.)

2. Raise hood.

3. Check coolant level:

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· If engine is hot, coolant should be up to "H" mark (A) on recovery tank.

· If engine is cold, coolant should be at "L" mark (B) on recovery tank.

4. Remove cap (C) from recovery tank if coolant is low. Add ethylene glycol antifreeze (without stop-leak additive) and water in a 50:50 ratio to bring coolant up to proper level.

5. Install and tighten recovery tank cap.

6. Clean debris from air intake screens and radiator.

7. Check condition of hoses. Check for leaks or loose connections.

Servicing Cooling System

c CAUTION: Avoid injury! The radiator will be hot and can burn skin. Built-up pressure may cause explosive release of coolant when the radiator cap is removed:

· Shut off the engine and allow to cool.

· Do not remove the cap unless the radiator and the engine are cool enough to touch with bare hands.

· Slowly loosen the cap to the first stop to release all pressure. Then remove the cap.

Draining Cooling System

1. Park machine safely on a level surface. (See Parking Safely in the SAFETY section.)

2. Allow engine to cool.

3. Raise hood.

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4. Loosen and remove radiator cap (A) slowly to release all pressure, then tighten cap.

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5. Locate hose (B) between water pump and cylinder head on left side of engine. Loosen upper hose clamp with pliers.

6. Position a bucket below the hose.

7. Remove hose from fitting on cylinder head. Drain all coolant into bucket.

NOTE: If pressure has been released from radiator and cap is tight, only a small amount of coolant should escape from cylinder head.

8. Install hose and clamp to cylinder head fitting after coolant has drained completely.

9. Flush the cooling system.

Flushing Cooling System

1. Remove radiator cap.

2. Fill cooling system with clean water and John Deere Cooling System Cleaner, or John Deere Cooling System Quick Flush or an equivalent. Follow directions on the can.

3. Install and tighten radiator cap.

4. Start and run engine until it reaches operating temperature.

5. Stop the engine.

6. Drain cooling system immediately before rust and dirt settle.

7. Install hose and clamp.

Filling Cooling System


IMPORTANT: Avoid damage! Using incorrect coolant mixture can damage the radiator: · Do not operate engine without coolant or with plain water. · Use antifreeze approved for use in aluminum engines. · Do not exceed a 50% antifreeze mixture for the coolant. · Do not pour coolant or water into radiator when engine is hot.

1. Allow radiator to cool.

2. Remove radiator cap.

3. Fill cooling system. Coolant capacity is 3.1 L (3.3 qt).

4. Install and tighten radiator cap.

5. Run engine until it reaches operating temperature.

6. Stop the engine.

7. Check coolant level while engine is hot and after cooling to ensure proper level in recovery tank. If necessary, fill recovery tank to proper level.

8. Tighten hose clamps if necessary.

9. Lower the hood.

Checking Coolant Hoses

NOTE: Visually inspect hoses for cracks and wear. Squeeze hoses to check for deterioration. Hoses should not be hard and brittle, nor soft or swollen. Drain cooling system and replace hoses as needed. Replacement of the coolant overflow line does not require draining the system.

1. Park machine safely. (See Parking Safely in the SAFETY section.)

2. Allow engine to cool.

3. Remove hood.

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4. Remove air intake screen (A).

5. Loosen hardware securing front shield (B). Swing shield downward.

6. Remove air cleaner cover and filter element.

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7. Check radiator hose (C). Replace as needed. Check tightness of clamps (D).

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8. Check radiator hose (E) and overflow hose (F) at right side of engine. Replace as needed. Check tightness of clamps (G).

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9. Check coolant hose (H) between water pump and cylinder head on left side of engine. Replace as needed. Check tightness of clamps (I).

10. Assemble air cleaner.

11. Swing front shield into place and tighten hardware.

12. Install air intake screen.

13. Flush cooling system if necessary.

14. Fill cooling system.

15. Install hood.

Checking Spark Plugs

c CAUTION: Avoid injury! Touching hot surfaces can burn skin. The engine and components will be hot if the engine has been running. Allow the engine to cool before servicing.

1. Park machine safely. (See Parking Safely in the SAFETY section.)

2. Raise the hood.

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3. Disconnect spark plug wire (A) on each side of engine.

4. Remove spark plugs.

5. Clean each spark plug carefully with a wire brush.

6. Inspect spark plugs for:

· Cracked porcelain.

· Pitted or damaged electrodes.

· Other wear or damage.

NOTE: In Canada, replace spark plug with resistor plug only.

7. Replace spark plugs as necessary.

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8. Check plug gap (B) with a wire feeler gauge. To change gap, bend outer electrode (C).

· Gap must be 0.75 mm (0.030 in.).

9. Install and tighten spark plug. Tighten spark plug to 15 N·m (11 lb-ft).

10. Connect spark plug wires.

11. Lower the hood.

Adjusting Carburetor

NOTE: Carburetor is calibrated by the engine manufacturer and is not adjustable.

If engine is operated at altitudes above 1829 m (6,000 ft), some carburetors may require a special high altitude main jet. See your John Deere dealer.

If engine is hard to start or runs rough, check the troubleshooting section of this manual.

Possible engine surging will occur at high throttle with transmission in "N" neutral and mower engagement lever disengaged. This is a normal condition due to the emission control system.

After performing the checks in the troubleshooting section and your engine is still not performing correctly, contact your John Deere dealer.

Replacing Fuel Filter

c CAUTION: Avoid injury! Fuel vapors are explosive and flammable:

· Do not smoke while handling fuel.

· Keep fuel away from flames or sparks.

· Shut off engine before servicing.

· Cool engine before servicing.

· Work in a well-ventilated area.

· Clean up spilled fuel immediately.

NOTE: Change filter when fuel is low to prevent excessive fuel spillage.

1. Park machine safely. (See Parking Safely in the SAFETY section.)

2. Allow engine to cool.

3. Raise the hood.

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4. Place a drain pan under fuel filter (A).

5. Note direction of arrow on fuel filter so new filter can be installed in the same direction.

6. Use a pliers to slide hose clamps (B) away from fuel filter.

7. Disconnect hoses from filter.


IMPORTANT: Avoid damage! Incorrect installation of fuel filter may cause engine damage. Install the filter with the arrow pointing in the direction of fuel flow for proper operation.

8. Make sure arrow on new filter is pointing in the direction of fuel flow. Connect hoses to filter.

9. Slide hose clamps in position to secure filter.

10. Check for leaks.

11. Lower the hood.

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