Diesel Transmission Repair & High-Performance Builds
Engineered for High Torque and Heavy Loads
Diesel engines are built for power, but that power puts incredible strain on your drivetrain. At Harmon Performance Transmission & Diesel Repair, we specialize in diesel transmissions that can keep up with the massive torque output of modern diesel engines. Whether you use your truck for heavy towing, daily work, or competitive performance, our ASE-Certified Technicians provide the reinforced builds and expert repairs necessary to keep you moving.
Our Diesel Transmission Services
Custom Diesel Performance Transmissions
We build and modify transmissions specifically for diesel performance applications. These custom units are engineered to handle the high-torque demands and heavy loads that would shred a stock gearbox, providing enhanced durability and reliable power delivery.
High-Torque Clutch Kits
For manual diesel trucks, a standard clutch isn’t enough. We offer high-torque clutch kits designed to withstand the increased stress and power of diesel engines, ensuring positive engagement and long-lasting performance.
Heavy-Duty Torque Converter Upgrades
Maximizing efficiency in a diesel application starts with the torque converter. Our upgrades are designed to handle extreme torque while delivering smooth, powerful acceleration and improved towing capability.
Performance Gear Ratio Tuning
Optimizing your gear ratios is essential for getting the most out of your diesel’s power band. We provide tuning services to enhance acceleration and towing performance, ensuring your transmission is perfectly matched to your engine’s output.
High-Efficiency Cooling Systems
Diesel engines generate significant heat, which is the primary enemy of transmission fluid. We install and maintain high-efficiency cooling systems to keep your operating temperatures in check and prevent overheating during heavy pulls.
Reinforced Internals & Components
To meet the extreme demands of diesel performance, we utilize reinforced components, including heavy-duty gears and high-strength internals. These upgrades significantly improve the overall reliability of your drivetrain.
Fluid Maintenance & Performance Testing
Regular maintenance is the key to diesel longevity. We offer comprehensive fluid changes and inspections, followed by thorough performance testing to ensure your transmission meets our high standards for power and reliability.
The Harmon Diesel Advantage
We understand the specific needs of Cummins, Duramax, and Powerstroke owners.
- Certified Expertise: We are TransGo Tech Certified and ATSG members, giving us the technical edge in diesel valve body and internal repairs.
- Work & Play Ready: We build transmissions that work as hard as you do, from the job site to the pulling track.
- Family-Owned Service: Get the personal attention and transparent recommendations that only a local, family-owned shop can provide.
Strengthen Your Diesel Drivetrain
Don’t wait for your transmission to slip under pressure. Upgrade your performance or schedule a repair today.