Explain how the warranty works through John Deere. Are they replaced free or prorated and how long are does the warranty last?

There are 3 types of warranty cases from John Deere:

1. John Deere serial numbered unit shipped from the Factory with Tweels installed: Same as vehicle.
2. Tweels sold as attachments separately or installed onto a John Deere serial numbered unit: 12 months
3. Tweels sold as a part number over the counter: 6 months.