At Certified Diesel Transmission, we take pride in the quality of our work and the reliability of our products. That's why we offer a comprehensive warranty on all transmissions we sell. Our optimized stock transmission comes with a 3 year, 100k warranty, while our stage 2 and 3 transmissions come with a 2 year, unlimited mileage warranty. Please note that for stage 2 and 3 transmissions, transmission tuning is required, and a hot flush must be done upon installation.