Gearboxes and differentials. A gearbox provides speed and torque conversions from a rotating power source to another device using gear ratios. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. A differential is capable of transmitting torque and rotation through three shafts.

Tractive AB Sweden

Tractive AB Sweden

Tractive designs and builds premium quality motorsport gearboxes, with top class performance and functionality, available at competitive prices. At the same time the gearbox casings are as lightweight as possible but still offering great torsional stiffness. Tractive is a company which represents state of the art technology in the field of development and manufacture of sequential motorsport gear boxes and differentials for rally and racing cars. Over 95 % of all parts are made in house which enables perfect control over quality and standards. Tractive AB in Sweden delivers to satisfied customers worldwide and since the introduction of the new modular design Tractive sequential gearboxes in 1995 the products have continued to grow in demand.


The Tractive concept

The modular concept of Tractive gearboxes allows using the same parts for rear and front wheel drive transmissions. The shift mechanism, type of ratios, dog rings and associated parts are the same for the RD90 and SD90 gearboxes. This concept is the corner stone for very cost-efficient manufacturing of high quality gearboxes in relatively small numbers.

The basic layout for RD90 and SD90 gearboxes avoids all major problems related to thermal and mechanical properties of traditional layouts. The main housing of the SD90 casing is, basically, a fully-machined piece of aluminium billet, combining minimum weight with superior mechanical, dimensional and thermal stability.

The gear set is enclosed in a housing which is completely round on the inside. The torsional forces are optimally absorbed. When gears are meshed and working with each other on rotating shafts, the shafts will bend. When the gearbox warms up, components expand differently. With a symmetrical, cylindrical housing, as in the Tractive gearboxes, the effects of the thermal expansion are minimized. Another important advantage of the cylindrical housings is the more efficient oil lubrication combined with reduced pumping losses.

Production gears

The material

All components used for the housings are machined from billets of air craft quality aluminium (590 N/mm2 UTS), to create light and very rigid units. Ultra clean single melted steels or Vacuum Arc Remelted (VAR) is used for gears, gear shafts, and other case hardened highly stressed components. If required, 18CrNiMo 7-6 steel is used for lower cost gears, gear shafts, and other case hardened highly stressed components. All gears are dual shot peened.

Aerospace grade materials as BS S155 (300M) Vacum Arc Remelted (VAR) steel is taken for high torque drive shafts. Ultimate tensile strength is 1900 - 2100 MPa. Drive shafts are made from Ovako Ovax 500 produced in ultra clean process.

Only stress relieved (Swiss produce) highest quality aerospace alloy materials are used for gearbox casings and covers. The specification is higher than for 7075 aluminium alloy. No castings or magnesium alloys are used.

CAD design

The gears

Gears are a whole science and Tractive masters this fascinating science. When designing the gears it is not enough to just make them fit and strong enough to handle the torque they should transfer. The gears should also work with as little friction against each other as possible. Precision in design and manufacturing is crucial. The smaller the manufacturing tolerances, the better quality will result from. Tractive makes all the gears in-house and grind them to very tight tolerances in our Höfler gear grinding machine. The Höfler machine produces DIN1 - 2 quality on a daily basis.

All RD90 and SD90 gearbox have 90.0 mm shaft centre distance. The SD90 has a 130.6 centre distance between pinion and ring gear.

Tractive uses SolidWorks® for all 3D modelling, FEM analysis, stress calculations, 2D drawings, exploded spare parts drawings, photo realistic pictures, etc.

M2 Automotive

The distribution

M2 Automotive has been officially named exclusive distributor for Tractive products in Germany and the Benelux states (Belgium, Netherlands and Luxembourg). M2 Automotive are proud to represent such a great product from December 2009 on.

Please do not hesitate to contact us to learn more about the excellent products of Tractive. We are looking forward to provide you with high performance solutions based on gearboxes and differentials of Tractive.

Please also visit our shop, to choose the best fitting solution for you. Or contact us for a custom tailored solution.

Back to Top Top

Home | Imprint | Contact | Links