All components used in our gearboxes are made with the very best European, Japanese and American equipment. The manufacturing plant and processes used to manufacture every HGT Precision Sequential Gearbox include:

  • 4 & 5 Axis horizontal and vertical machining centers
  • 4 Axis CNC turning machines
  • CNC gear shaping
  • CNC gear grinding
  • Broaching & Slotting
  • Wire cutting
  • Surface grinding
  • Bore grinding
  • Cylindrical grinding
  • Deburring
  • Micro polishing
  • Heat treatment


As you’d expect, the factory is ISO 9001- 2008 accredited, use Japanese quality systems like 5S, Kanban, Kaizen, have Lean Manufacturing and ERP systems to optimize and control drawings, documentation and work flow. This creates efficiency and consistency in the manufacturing process.

We could have saved money and sandcast our gearbox cases, but we chose CNC milling as we wanted the ultimate in strength and preciseness. Our gearbox casings start off as 60 kg blocks of billet 7075-T6 aluminum alloy. The robotic repeatability of the CNC machines allows us to reduce some of our tolerances down to just 5 microns. CNC milling creates a surface you simply cant get with casting. There’s no rough sand cast marks, no ridges and valleys, no pin holes or porosity, just a super smooth CNC finish. 

Our race transmissions contain only the highest quality precision components, controlled to finite tolerances, using only the highest grade of materials with documented monitored and controlled processes.

Our gear quality is DIN 6. Gear profiles are diamond ground on high technology gear grinding machines, with our gears having uniquely designed profiles for additional noise and heat reduction. Many other brands of race transmissions only have finished hobbed standard profile gears...meaning their gear quality is around DIN 10-12. The lower the DIN number, the higher the accuracy of the gear and the better it performs in extreme conditions.

What's the difference you may ask?

Well to begin with, diamond ground gear profiles have a smoother polished surface finish compared to finished hobbed gears, meaning less friction, so generate less heat. When we grind a gear after heat treatment, we can remove the distortions created by the heat treatment process meaning we maintain much smaller tolerances for the gear tooth allowing them to run more accurately in the gearbox.

This vastly improves contact and load of each individual tooth, which translates into better transmission of power, lower noise levels, less wear, lower running temperatures, and higher overall performance.