Tractive RD90 RWD sequential shift gearbox. 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.

Tractive RD90 rear drive sequential shift gearbox

Tractive RD90 rear drive sequential shift gearbox

Tractive RD90 rear wheel drive sequential shift gearbox

The RD gearboxes have a very consistent, smooth and reliable shift mechanism, and consequently dog ring life is exceptionally good. The efficient gear shift will help you drive faster. The casing from a billet of air craft quality aluminium, forms a light and very rigid unit. High quality precision ground gears gives an excellent life time of the gearbox with minimum maintenance. Maintenance is very simple as the layout allow for the complete gear set to be removed from the car in just a few minutes. Proven reliability and winning performance, the RD gearboxes offer you the best!


Number of speeds: RD905: 5 forward, 1 reverse
RD906: 6 forward, 1 reverse
Gear positions: RD905: R-0-1-2-3-4-5
RD906: R-0-1-2-3-4-5-6
Recommended max engine torque: 550-600NM
Weight: RD905: 30 kg
RD906: 35 kg
Housing design: A symmetric design ensures thermal stability and a uniform deflection of the housing during high loads. A natural and favourable load path is designed into the whole layout. All parts are machined from high tensile air craft quality aluminium. No castings are used whatsoever.
Clutch shaft: A separate clutch shaft drives the input shaft via a splined coupling. Different lengths and spline configurations are possible. The standard Ford 1”-23 spline is preferred for a shorter lead time, while we certainly can make any type of spline to any type of clutch.
Clutch release mechanism: Not integrated with the gearbox. Usually fitted in the standard bellhousing.
Clutch rings (dogrings): Tractive standard with 90 mm O.D. with radiused corners for long life and good durability.
Gear selection mechanism: Sequential shift mechanism extensivley developed by Tractive from Honda MX-bike origins.
Cockpit Gear Lever: Tractive sequential shift gear lever with return springs.
Connection between gear lever and gearbox: Through 8 mm stanless steel rods, either direct or over a bell crank on the prop-shaft tunnel.
Reverse gear engagement: With clutch ring shared with 1:st gear. Note! No sliding gears, no chips or swarf in the gearbox.
Reverse gear release mechanism: A separate lever on the gear lever must be operated to release engagement of reverse gear.
Gear wheel width: 17 mm for all gears.
Ratios: See Ratio charts. Coming soon.
Drop Gears: The RD905 and RD906 gearbox have a drop gear arrangement to compensate for various rear axle ratios, or to fine tune the top speed and acceleration characteristics. Two gear situated behind a cover at the rear of the gearbox are easily replaced to alter the overall ratio of the gearbox. 13 different drop gears are currently in production.
Bearings: Standard type SKF cylindrical roller bearings for input and output shafts. Ball bearings for selector drums.
Bearings in clutch gears: INA cage type needle roller bearings.
Lubrication: Wet sump. A GL5 spec. transmission oil is recommended.
Seals: Nitril as standard or Viton alternatively PTFE-lipped low friction seals on request.
Shot peening: All gears and dogrings are shot peened unless otherwise specified by the customer. The cost for shotpeening is included in the quoted price.
Surface treatment of casing: All parts making up the casing are anodized in black colour.


Due to its modular design, the Tractive RD90 can be adapted to virtually any engine / car combination without need for new patterns or extensive redesign. RD90 is used in rear-wheel drive cars. Different versions of the RD90 gearbox fit very different cars, from MKII Escorts with some 220Nm to V8 engined cars with 900Nm of torque. RD90 gearboxes are now fitted to most front runners cars in the domestic series, winning events in the Swedish Championship.

Application list, March 2011

Part Number of front cover Car
58310500 Volvo M45
58310700 Ford type 9
58311100 Ford ZF
58311400 BMW 320 compact
58311500 Camaro
58311600 Toyota Corolla twin cam
58311700 Ford Cosworth 10 deg left tilt (ex right)
58311800 Ford Cosworth 10 deg right tilt (ex left)
58311900 Ford type 9 right tilt 7 deg (ex left)
58312000 BMW M3 Getrag
58312100 BMW ZF
58312300 Ford MT75
58312400 Opel Kadett / Ascona CIH engine
58312500 Ford type 9 left tilt 7 deg (ex right)
58312600 BMW 6cyl M20/M50
58312700 Nissan Skyline manual box R32,R33,R34
58312900 BMW vertical V6 M20, M50
58313000 Ferrari Maranello 550
58313100 Mercedes ”Tobias”
58313200 Mazda Wankel
58313300 Universal quick change
58313600 Universal quick change offset lug
58313700 Toyota 1600
58314200 Mercedes DTM
58314400 Nissan 350Z G35

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