Truck and Bus

Worldwide, the truck and bus industry is focusing on automating the gear shift process, to improve efficiency, reduce CO2 emissions, minimise driver skill requirements and extend service life by eliminating abuse.

The goal is to reduce the total life cost of truck and bus transmissions, and the use of automated shifting draws on many of DSD’s core skills. We are accustomed to designing for the long service life that characterises this sector: typically 400,000 miles for medium duty and over a million miles for a heavy duty application.

Transmission Control

DSD has a skilled control team with experience of AMTs and DCTs, from basic algorithm design, through plant modelling / simulation, diagnostics design to calibration and validation for production. We also have strong system integration skills, vital for customers new to automation and electronic control of transmissions.

Automating Manual Transmissions

DSD provides both complete design and bolt-on automated shifts suitable for the conversion of existing manual transmissions. AMTs demand specialised skills in shift system / actuator design and control system development. DSD’s particular expertise in the control of AMTs is directly applicable to this new generation of truck and bus transmissions.

Base Transmissions

DSD’s expertise extends from target setting (e.g. refinement, shift quality) through the definition of optimum specifications, concept design up to production engineering and design for manufacture. Our detail component expertise includes gear design for low noise with highest efficiency, whether spur, helical, planetary or bevel gears. We have designed synchroniser components for many of the world’s premier manufacturers, and used our skills to resolve often persistent problems in gearshift systems for major truck OEM’s.


The test and development facilities at DSD are suited to commercial vehicle transmissions and drive axles. This includes spin, tilt and efficiency test rigs, and an environmental shaker rig, to test hybrid power packs for example. It can accommodate up to 600kg, with the ability to apply single-axis vibration at temperatures between -55C to +150C. It also includes a four square 20,000Nm test rig. The DSD team also has huge practical experience of developing and solving problems in a wide variety of transmissions and final drives.