About Us

R&C Diesel Transmission is a high-performance diesel and transmission shop located in Sonoma County, CA. Owner/Operator Ryan Gully has been in the diesel performance industry for 10 years and counting. Ryan began working in the diesel industry back in 2014 when he opened a small performance and repair shop. Over the years this shop grew to be one of the most successful repair and performance shops in the area. During this time Ryan became frustrated with quality issues and overpriced transmissions from other suppliers. Fast forward to now, R&C Diesel Transmission is the solution for the highest quality of parts, infinite customization, and unparalleled quality control, at a fair price.