Next Gen Diesel's Performance transmissions feature a two-year unlimited mileage warranty. Shafts and gears ARE NOT COVERED against breakage! Customer is responsible for all costs associated with damage caused by broken shafts. Shaft breakage is considered abuse and is NOT warrantied under any circumstances! All warranties are non-transferable and do not cover abuse to the item. This includes any unit used in excess of our stated power ratings. Also the use of a trans-brake or Nitrous on any of our converter is not authorized unless the appropriate upgrades are purchased. Some of our items may also need additional upgrades as deemed suited by Next Gen Diesel in order to be installed in some applications. If the recommended upgrades are not purchased and the unit fails due to the non-upgraded parts, the respective warranty will be voided. Warranty does not include labor for the removal or installation of any product, including defective items. The Next Gen Diesel warranty does not cover any costs associated with a failure or defective item, including but not limited to the following: downtime, rental car, labor, storage fees, fluids, towing charges, travel costs and consequential damage to the transmission or driveline. Any defective item must be sent back to Next Gen Diesel, freight prepaid, and upon receipt will be inspected for damage. Next Gen Diesel will at it's sole discretion either repair or replace the defective item.