RD4

4-speed H-pattern Dog-change Gearbox

Description

From our popular RD6 comes the newest addition, the RD4. A light weight, reliable, robust 4-speed dog-change H-pattern gearbox with a high torque capacity, primarily designed for front-engine, rear-wheel-drive race cars. Recently found in a few Trans Am and Pro Touring race cars.

Key Design Objectives

To be a highly adaptive, simple and reliable yet robust in-line transmission with a high torque capacity, and the ability to be used in past, present and future performance vehicles in a vast range of applications.

Features

Dog-change gearbox primarily designed for use in front-engine, rear-wheel-drive race cars.
Holinger Engineering’s Unique ‘Double Interlock’ system, which locks the unselected gears out in 2 locations. The dreaded selection of “2 gears at once” is eliminated in the Holinger RD gearbox range, making it both safer and more cost effective.
Available only in H-Pattern.
Torque rating for endurance events is 880Nm (650ft.lb). This is not a failure rating but an indication of life expectancy in long events with 100% reliability.
The gearbox is fitted with 4 forward gears and a reverse gear. All forward gears are profile ground for increased efficiency and durability. All gears are removable from shafts with an extensive range of ratios available.
Shifting is via an integral steel gear-lever, mounted directly to the top of the gearbox. Bend designs can be customised to a driver.
The internal lubrication system consists of a magnetic / paper element filter, an oil pump with provision for an external oil cooler and an integral spray bar to feed cooled oil directly onto the gears and through-shaft lubrication.
Input is via a removable quill-shaft which can be customised to suit individual requirements. Easy to replace from outside of the gearbox, no disassembly required.
Output is via a slip yoke which can be customised to suit individual requirements.
Case hardened nickel chrome steel is used for all gears and shafts.
The selector forks are manufactured from high tensile, nitrided steel.
Casings are sandcast Aluminium alloy, heat treated to T6 specifications.
O-ring seals are used on all joint faces.
Gearbox weight is ~30kg (66lbs)