RD90 RWD sequential shift gearboxes

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. Read more ».

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!

Download pdf workshop manual for RD906 (33Mb).

  • Specifications

  • Applications

  • Tech info

  • Ratio charts

  • Inquiry

  RD905 RD906
Number of speeds: 5 forwards,
1 reverse
6 forwards,
1 reverse
Gear positions: R-0-1-2-3-4-5 R-0-1-2-3-4-5-6
Recommended max engine torque:  
Weight:  30 kg  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 lifge 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
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.
Gear selection mechanism: Sequential shift mechanism extensivley developed by Tractive from Honda MX-bike origins.
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 Vition 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.

Testimonials


Phil Collins, a consistent top runner in the British Championship, is happy with his RD906 6-speed gearbox. 



“I had a Motorsport business and ran Opels Fords and Toyotas, but the Tractive Transmission is the most impressive piece of engineering I have encountered”.

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