Passenger Cars

DSD’s passenger car experience includes the engineering of all-new transmissions and drivelines, torque efficiency upgrades of existing units and the resolution of issues arising with existing products.

The company recognises that CO2 legislation is driving industry trends such as engine downsizing and the hybridisation of vehicles, so DSD thoroughly understand the context in which our customers operate and the challenges they face.

Whatever your issues may be, DSD has probably dealt with very similar ones successfully for other customers, often in several different applications.

Complete transmission engineering

DSD track record of delivering driveline projects is achieved by having world class analysis and simulation capability, combined with deep technical knowledge of key transmission technologies, such as clutches, synchronisers, gears, bearings, hydraulics and selector systems.

The company’s familiarity with high volume manufacturing, undertaking plant reviews for a number of customers, means we understand the challenges and constraints of production. This understanding enables us to input this information back into the engineering.

DSD’s ability to procure, draw, purchase and build prototype assemblies, means we can deliver a complete service, from concept design, through prototypes to production launch support.

Efficiency improvement

DSD frequently undertakes programs to deliver increased efficiency from existing axles and transmissions, to help our customers improve overall vehicle fuel economy and CO2 emissions, delivering measurable improvements.

In one example, we reduced oil churning losses in a current production high volume manual transmission without compromising durability.

The company evaluates and calculates the loss of each individual component in the system. By comparing all the available options for each individual element DSD can pick the best solution and reduce losses within the transmission. It can also evaluate and optimise the flow of lubricant to ensure the minimal required amount of churning occurs, reducing parasitic losses and increasing efficiency.


DSD has particular strengths in the development of Shift Quality and the resolution of NVH issues.

Gear shifting is the key area where a driver will gain a tangible impression of transmission quality in their vehicle, particularly with automatic transmissions, such as AMTs and DCTs, where the lack of input from the driver can highlight issues. Our experience of shift system design, control and calibration includes hydraulic, electric and manual operation and makes a significant contribution to the perceived quality of the whole transmission.

Typical NVH problems that we solve include gear whine, rattle, clatter, driveline boom, shunt and clunk/clonk, clutch damper tuning, manual gearshift quality and gear lever tizz. Our experience in all aspects of transmissions and transmission integration has enabled us to deliver solutions to customers within very short timescales.

Transmission and axle upgrades

DSD engineers upgrades on existing products such as improved gear rolling and churning losses and increasing the torque capacity of the driveline.

Upgrading products can create new problems. DSD is likely to have overcome similar challenges before and can quickly identify root causes and present practical solutions.