Swapping an injection pump on a 6068 John Deere? Follow this 10-phase procedure to ensure your timing is factory-perfect using the JDG254A timing tool.

Why Mechanical Accuracy Wins

Unlike fully electronic engines, the mid-range JD 4045 and 6068 series rely on the mechanical relationship between the gear train and the pump. The JDG254A acts as the master reference, ensuring that when the pump fires, the piston is exactly where it needs to be.

The 10-Phase Timing Procedure

1. TDC Verification: Rotate the crankshaft manually to Top Dead Center for cylinder #1.
2. Insert JDG254A: Place the tool into the timing port on the engine block/timing cover.
3. Find the Notch: Slow down the rotation until the tool seats firmly into the crankshaft timing notch.
4. Lock the Crank: With the tool seated, the crankshaft is now mechanically locked at TDC.
5. Pump Preparation: Loosen the injection pump gear mounting bolts.
6. Align Pump Internal Marks: Ensure the internal timing marks on the pump line up with the housing.
7. Positive Indexing: Tighten the gear train bolts, ensuring zero movement thanks to the JDG254A.
8. Remove the Tool: ⚠️ Crucial: Always remove the JDG254A before attempting to turn the engine.
9. Manual Rotation: Rotate the crankshaft two full turns by hand to check for mechanical interference.
10. Final Re-Check: Re-insert the tool at TDC to verify the timing hasn't drifted.

Pro Warning: Avoid Expensive Errors

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