A cracked or damaged windshield on your John Deere excavator doesn’t just obstruct your view, it’s a serious safety hazard that can compromise your productivity and your operator’s protection. Whether you own a John Deere 35G or another compact or mid-size excavator model (like the 17G, 50G, 60G, or 85G), replacing the upper cab glass is a straightforward job with the right tools and method.
This guide walks you through the full process of replacing the upper front windshield using industry-approved practices demonstrated on a 35G.
Why You Might Need to Replace Your Excavator Windshield
Excavator windshields take a beating from falling debris, hydraulic blowouts, tree branches, and jobsite impact. A damaged cab glass can:
- Obstruct visibility and reduce safety
- Fail inspection standards
- Let in rain, dust, or cold air
- Risk shattering during operation
Replacing the glass promptly prevents long-term issues and keeps your machine safe and compliant.
What You’ll Need
Here’s what’s typically required to replace an upper cab windshield:
Tools & Supplies:
- 10mm socket wrench (to disconnect wiper and mounting bolts)
- 13mm wrench (for wiper arm removal)
- Cut-resistant gloves (Kevlar preferred)
- Sharp retractable knife
- Plastic trim removal tools
- Urethane adhesive (for bonding glass to frame)
- Clear silicone sealant (for molding)
- Masking tape (to hold glass while curing)
- Replacement glass (aftermarket glass will save you money with no loss in quality)
- Replacement molding (if needed)
- Grease (for roller mechanism)
Step-by-Step Guide to Replacing the Windshield Glass
1. Disconnect the Wiper and Power Source
- Start by disconnecting the power to the windshield wiper motor using a 10mm socket.
- Then remove the wiper arm with a 13mm wrench.
- Set both aside for reassembly.
2. Remove the Existing Glass
- Open the window and carefully lift it out of its track.
- Watch for rollers or bushings as they can fall off during removal, so keep track of them.
- Remove four mounting bolts from the corners of the glass frame.
- If the lower seal is glued, cut it carefully using a retractable knife. Use only shallow pressure (⅜" deep) to avoid cutting into the frame.
3. Cut the Glass Out of the Frame
- Flip the glass over and continue cutting the seal from the opposite side.
- Once the seal is sliced, carefully separate the glass from the frame.
- If you plan to keep the old glass, place it gently on foam, wood, or blankets. Never place it directly on concrete because that can cause breakage.
4. Clean and Prepare the Frame
- Remove any old adhesive, silicone, or urethane from the frame edges.
- Clean the surface thoroughly.
- Identify the wiper hole seal and remove and clean it separately before reuse.
5. Attach New Molding and Prepare the New Windshield
- Push the molding onto the new glass edge by hand or use a rubber mallet to ensure a snug fit.
- Align the molding so that the longer flap (if present) faces outward.
6. Apply Urethane Adhesive to Frame
- Apply a bead of urethane adhesive to the frame where the new glass will mount.
- Avoid overapplying, as too much glue creates a mess and weakens the bond.
- Ensure alignment with mounting holes before setting the glass.
Important: Never mix urethane and silicone. Use urethane for glass bonding and silicone for sealing molding edges only.
7. Install the New Windshield
- Gently lower the glass into the frame.
- Use masking tape to hold it in place during curing.
- Use silicone to reseal the molding around the edges. Apply two strips of masking tape to keep the seal neat, then peel it after smoothing.
8. Reinstall the Window Assembly
Once cured (usually overnight), reinstall the glass into the excavator:
- Apply grease to the roller mechanism to help with smooth movement.
- Insert the lower rollers first, then align and lock the top into the track.
- Reattach the mounting cleats in the corners. Make sure they are flush with the track.
- Reconnect the electrical wiring for the wiper.
9. Final Touches
- Reinstall the wiper arm and blade.
- Peel off the remaining protective film or tape.
- Lock the glass into place and test movement to ensure proper fit.
Which John Deere Excavators Does This Apply To?
This windshield replacement method applies to many John Deere compact and mid-size excavators, including but not limited to:
- 17G, 26G, 30G, 35G, 50G, 60G, 85G, and more
- Some steps may vary slightly depending on cab size and window configuration (hinged vs. fixed, full vs. split glass)
Always verify dimensions and mounting hardware in your operator’s manual or parts catalog before starting.
FAQ: Frequently Asked Questions
How much does it cost to replace a John Deere excavator windshield?
Expect to pay between $400–$900 USD for polycarbonate replacement glass. OEM glass will cost more, especially if curved or tempered, so aftermarket glass is a great affordable option. Aftermarket glass often meets or exceeds OEM quality for a fraction of the price. Parts Online offers a wide selection of aftermarket glass for John Deere Excavators. Shop aftermarket John Deere glass here.
Can I install a polycarbonate windshield instead of glass?
Yes. Many operators prefer polycarbonate for its impact resistance. It’s lighter, safer, and less likely to shatter, but may scratch more easily unless it’s hard-coated.
How long should I wait before operating the machine?
Let urethane cure for 12–24 hours before putting the machine back into operation. Always follow adhesive manufacturer guidelines.
Can I do this by myself?
Technically yes, but it’s much easier with two people. The glass is awkward to position, and holding it steady while aligning rollers is a challenge solo.
Conclusion
Replacing the windshield glass on your John Deere excavator is a DIY-friendly job with the right preparation and safety gear. It’s a valuable skill for operators who want to save on service calls and minimize downtime.
When installing replacement glass always remove carefully, clean thoroughly, glue precisely, and reinstall patiently.
For aftermarket glass compatible with John Deere excavators, Parts Online has you covered. We only sell aftermarket glass that meets or exceeds OEM quality, but do so at a fraction of the OEM price.