How to Replace the Gearbox on a 60-Inch JD Mowing Deck

Home Improvement Admin February 11, 2025

Replacing the gearbox on a 60-inch John Deere mowing deck is a task that requires careful attention to detail and adherence to safety protocols. Here’s a step-by-step guide to assist you:

1. Preparation:

Safety First: Ensure the mower is on a flat surface. Disconnect the spark plug to prevent accidental starts.
Gather Tools: You’ll need wrenches, screwdrivers, pliers, and possibly a gear puller.

2. Remove the Mower Deck:

Detach the Deck: Lower the deck to its lowest position. Disconnect the attachment pins and lift arms. Slide the deck out from under the mower.

3. Access the Gearbox:

Remove Covers: Take off any protective covers to expose the gearbox.
Disconnect the PTO Shaft: Unbolt the Power Take-Off (PTO) shaft from the gearbox.

4. Remove the Old Gearbox:

Unbolt the Gearbox: Locate and remove the bolts securing the gearbox to the deck.
Lift the Gearbox: Carefully lift it off the deck.

5. Install the New Gearbox:

Position the New Gearbox: Align it with the mounting holes on the deck.
Secure with Bolts: Tighten the bolts to the manufacturer’s specifications.

6. Reassemble the Mower:

Reconnect the PTO Shaft: Ensure it’s securely attached to the new gearbox.
Replace Covers: Reinstall any protective covers removed earlier.
Reattach the Deck: Slide the deck back under the mower and reconnect the lift arms and attachment pins.

7. Final Checks:

Lubrication: Check the gearbox oil level and add oil if necessary.
Test Run: Reconnect the spark plug. Start the mower and engage the blades to ensure everything operates smoothly.

Recommended Replacement Part:

For a suitable replacement, consider the AM143310 Gearbox, compatible with John Deere models 425, 445, and 455 with 48″, 54″, or 60″ decks. This gearbox is available from various suppliers, including Flip Manufacturing.

Additional Resources:

For comprehensive guidance, consult the official John Deere service manual for your specific mower model. This manual provides detailed diagrams and safety information.

Safety Reminder:

Always prioritize safety. If you’re uncertain about any step, consider consulting a professional technician.

By following these steps, you can effectively replace the gearbox on your 60-inch John Deere mowing deck, ensuring continued performance and longevity.