Service Transmission
Checking Transmission (Z225)
The Z225 transmission is a sealed component. No maintenance is required on this transmission. If you suspect any transmission problems, please contact your authorized dealer.
Transmission Oil
Z425
DO NOT use type “F” automatic transmission fluid.
Z645
NOTE: Machine is filled with John Deere Low Viscosity HY-GARD® (J20D) transmission oil at the factory. Do not mix oils.
Use only Low Viscosity HY-GARD® (J20D) transmission oil. DO NOT use type “F” automatic transmission fluid.
IMPORTANT: Avoid damage! Use John Deere Low Viscosity HY-GARD® (J20D) transmission oil to reduce transmission noise and to increase response time for the hydraulics and power steering. |
John Deere Low Viscosity HY-GARD® (J20D) transmission oil is specially formulated to provide maximum protection against mechanical wear, corrosion, and foaming. It may be used in all operating temperatures.
Checking Transaxle Oil Level
Z225
The Z225 transmission is a sealed component. No maintenance is required on this transmission. If you suspect any transmission problems, please contact your authorized dealer.
Z425, Z645
1. Park machine safely on a level surface. (See Parking Safely in the SAFETY section.)
IMPORTANT: Avoid damage! Hot hydraulic oil will expand and show incorrect oil level. Check oil level: |
3. Locate transaxle oil reservoir (A) at rear of machine. Reservoir is marked FULL (B).
IMPORTANT: Avoid damage! Contamination can damage the hydraulic system. Clean thoroughly around reservoir fill cap before opening. |
4. If oil level is low, clean area around reservoir cap (C).
6. Add oil until level is at FULL mark on reservoir.
• Z425 - Use 15W-40 or 10W-30.
• Z645 - Use Low Viscosity HY-GARD® (J20D) transmission oil.
9. Operate machine forward and in reverse several times.
10. Park machine safely on a level surface. (See Parking Safely in the SAFETY section.)
11. Wait at least 3 minutes for hydraulic oil to cool.
12. Check oil level again. Add oil if necessary.
Changing Transaxle Oil and Filter
Z225, Z425
The transaxles on these models require no maintenance. If you suspect transmission problems, contact your authorized dealer.
Z645
1. Park machine safely on a level surface. (See Parking Safely in the SAFETY section.)
IMPORTANT: Avoid damage! Contamination can damage the hydraulic system. Clean thoroughly around reservoir fill cap before opening. |
2. Lift seat. Clean area around reservoir cap (A). Remove cap.
3. Place a drain pan under the machine. Loosen hose clamp on bottom reservoir hose and carefully remove hose from bottom of reservoir and drain hydraulic fluid from system. After reservoir is completely drained, install hose and secure with clamp.
4. Lift filter (B) and remove from reservoir.
5. Install new filter in reservoir. Ensure that it is firmly seated in bottom of reservoir.
6. Fill oil reservoir with approximately 7.5 L (7.9 qt) of John Deere Low Viscosity HY-GARD™ (J20D) oil.
9. Move throttle lever to the 3/4 fast idle position.
11. Run engine in full forward position for five minutes and then cycle motion control levers forward and rearward several times.
12. Stop the engine. Check oil level in reservoir. Add oil as necessary.
Checking and Adjusting Neutral Creep
Check neutral creep with engine running, motion control levers in the start/shutdown position, park brake off, and machine on level ground.
If the machine creeps forward or reverse while motion control levers are in the start/shutdown position, adjust the motion control lever linkages:
1. Park machine safely. (See Parking Safely in the SAFETY section.)
Z225, Z425 (Z425 steering shown)
Picture Note: Right side of machine shown with machine parts removed for a more clear image.
• On linkage side needing adjustment (right side shown), remove spring locking clip (A) and rod end (B) from pivot pin (C). Turn rod end (B) on rod (D) in (clockwise) to decrease forward creep and out (counterclockwise) to decrease reverse creep. Repeat procedure, as necessary, on opposite side. Install rod ends back onto arms and secure with spring locking clips.
Z645
• On linkage side needing adjustment, remove clip and washers (G). Rotate rod end (F) in (clockwise) to decrease reverse creep and out (counterclockwise) to decrease forward creep. Repeat procedure as necessary on opposite side. Install two washers and secure with clip.
Cleaning Transaxle Cooling Fans (Z225, Z425)
c CAUTION: Avoid injury! Compressed air can cause debris to fly a long distance.
• Clear work area of bystanders. • Wear eye protection when using compressed air for cleaning purposes. |
1. Park machine safely. (See Parking Safely in the SAFETY section.)
Picture Note: View from front of machine.
2. Clean transaxle fan fins (A) and around exterior of each fan with a rag, brush or compressed air.
Checking and Replacing Transaxle/Transmission Drive Belt
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c CAUTION: Avoid injury! Entanglement in a belt or sheave can cause serious injury. Stop engine and wait for all moving parts to stop.
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NOTE: The transmission drive belts are self-adjusted using a spring tensioner and do not require a tension adjustment.
Checking Transaxle/Transmission Drive Belts
1. Park machine safely. (See Parking Safely in the SAFETY section.)
2. Inspect drive belt (A) for excessive wear, damage or stretching while in position on all machine sheaves.
Replacing Transaxle/Transmission Drive Belts
Z225, Z425
1. Park machine safely. (See Parking Safely in the SAFETY section.)
3. Disconnect electric clutch wiring connector from main wiring harness connector.
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c CAUTION: Avoid injury! Components are installed under spring tension. Wear eye protection and use proper tools when installing and removing components with spring tension.
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Picture Note: Components viewed from top.
4. Insert a 1/2 in. ratchet or breaker bar into the square hole (A) on the idler arm (B), rotate the spring-loaded idler arm to relieve belt tension on the idler sheave (C) and remove the drive belt (D) from the idler sheave. Release the spring tension from the arm and remove the tool.
5. Remove the bolt, nut and belt guide (E).
7. Remove the drive belt (D) from the transaxle sheaves (G), intermediate sheaves (H) and engine sheave (I).
8. Position replacement belt onto engine sheave (I), intermediate sheaves (H) and transaxle sheaves (G).
9. Install belt guides (E, F).
10. Rotate the spring-loaded idler arm (B) and install the belt on the idler sheave (C).
11. Insert electric clutch wiring harness connector to main wiring harness.
Z645
1. Park machine safely. (See Parking Safely in the SAFETY section.)
3. Disconnect electric clutch wiring connector from main wiring harness connector.
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c CAUTION: Avoid injury! Components are installed under spring tension. Wear eye protection and use proper tools when installing and removing components with spring tension.
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4. Insert a 1/2 in. ratchet or breaker bar into the square hole (A) on the idler arm, rotate the spring-loaded idler arm to relieve belt tension on the tensioner sheave (B) and remove the drive belt (C) from the tensioner sheave. Release the spring tension from the arm and remove the tool.
5. Remove drive belt from transmission sheave (D), idler sheave (E) and engine drive sheave (F).
6. Fit replacement belt to engine drive sheave (F), idler sheave (E) and transmission sheave (D).
7. Rotate tensioner arm (A) against force of spring, and install drive belt to tensioner sheave (B).
8. Connect electric clutch wiring connector to main wiring harness connector. To aid in installation, install belt over pulley E last.
Adjusting Tracking
If the machine does not track in a straight line while going in full forward position, adjust the tracking:
NOTE: Use the 13 mm wrench (A) on one end of the deck height pin for adjusting the tracking bolts.
1. Park machine safely. (See Parking Safely in the SAFETY section.)
NOTE: Tracking bolts limit top forward speed. If both levers hit against the tracking bolts, turn both bolts counterclockwise equal amounts until only one bolt contacts the lever. This will achieve maximum forward speed.
• If machine tracks to the left, turn tracking bolt (B) clockwise.
• If machine tracks to the right, turn tracking bolt (C) clockwise.
Checking and Replacing Pump Drive Belt
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c CAUTION: Avoid injury! Entanglement in a belt or sheave can cause serious injury. Stop engine and wait for all moving parts to stop.
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NOTE: The transmission drive belt is self-adjusted using a spring tensioner and does not require a tension adjustment.
Checking Belt:
1. Park machine safely. (See Parking Safely in the SAFETY section.)
2. Remove engine drive sheave and belt shields (if installed):
a. Remove four bolts (A) and drive sheave shield (B).
b. Remove four bolts (C) and drive belt shield (D).
Picture Note: Components viewed from top.
3. Inspect belt (E) for excessive wear, damage or stretching while in position on all machine sheaves.
4. Install front and rear drive sheave shields if belt does not require replacement.
Replacing Transaxle/Transmission Drive Belts
1. Park machine safely. (See Parking Safely in the SAFETY section.)
2. Remove engine drive sheave and belt shields (if installed) if not already done:
a. Remove four bolts (A) and drive sheave shield (B).
b. Remove four bolts (C) and drive belt shield (D).
4. Disconnect electric clutch wiring connector from main wiring harness connector.
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c CAUTION: Avoid injury! Components are installed under spring tension. Wear eye protection and use proper tools when installing and removing components with spring tension.
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Picture Note: Components viewed from top.
5. Insert a 1/2 in. ratchet or breaker bar into the square hole (E) on the idler arm (F), rotate the spring-loaded idler arm to relieve belt tension on the idler sheave (G) and remove the drive belt (H) from the idler sheave. Release the spring tension from the arm and remove the tool.
6. Remove the bolt, nut and belt guide (I).
8. Remove the drive belt (H) from the transaxle sheaves (K), intermediate sheaves (L) and engine sheave (M).
9. Position replacement belt onto engine sheave (M), intermediate sheaves (L) and transaxle sheaves (K).
10. Install belt guides (I, J).
11. Rotate the spring-loaded idler arm (F) and install the belt on the idler sheave (G).
12. Insert electric clutch wiring harness connector to main wiring harness.
