Quaife Torsen (ATB) type limited slip differential unit for R5GTT, Clio 1 Williams/16v and all Clio 2 RS models.  Part number QDF6M.  This is the updated design without the welded outer case.

These fit all JC type gearboxes.  

They also fit JB type gearboxes with TAPERED differential bearings - they DO NOT fit gearboxes with ROLLER differential bearings. There is an easy way to check which box you have by measuring the driveshaft oil seal outer diameter - 'boxes with tapered bearings have a 70mm OD seal and 'boxes with roller bearings have a 56mm OD seal.

A LSD will improve your straight line traction and also aid handling by providing consistent traction. This torsen type differential provides smooth transition in torque without the grabbiness of a plate type LSD. 

The Quaife ATB Limited Slip Differential

Once installed, drivers will notice an immediate difference, as the Quaife (ATB) limited slip differential automatically biases the torque across the axle to the wheel with the most grip. Unwanted wheelspin and slip are greatly reduced, resulting in less understeer on front or four wheel drive machines and reduced oversteer on rear wheel drive vehicles. Rear wheel drive cars with a Quaife limited slip differential become more controllable during oversteer moments, enabling drivers to exploit the full potential of their machines for the first time, leading to a more exciting, rewarding and rapid driving experience.

On front wheel drive cars the Quaife ATB limited slip differential also delivers significant performance benefits during heavy braking. In this situation the Quaife differential’s inherent torque transfer characteristics work in reverse to transfer torque away from the locking wheel. This enhances deceleration, delaying the intrusion of electronic ABS systems and allowing drivers to brake later and deeper with the Quaife ATB limited slip differential than is possible with a standard ‘open’ differential unit.

Add these benefits together and it’s hardly surprising that in outright performance terms the Quaife ATB differential can make a remarkable difference compared to an ‘open’ differential. Back to back independent testing by Redline Magazine on a RenaultSport Clio 200 has proven that even on a short circuit lap times are reduced by over 2 seconds, making the Quaife ATB differential an excellent value for money upgrade.

Superior design, safe performance and service

Fully compatible with manufacturer electronic traction control and anti-lock braking systems, the Quaife ATB differential offers a number of key advantages in both functionality and service life compared to conventional plate-style LSD units.

Silent in operation (even during low-speed parking manoeuvres) the Quaife ATB limited slip unit never ‘locks,’ making it progressive, safe and user friendly. Unlike plate-style LSD designs there are no clutches, ramps, springs or other wear prone components to replace at regular intervals, because the Quaife ATB’s well-proven system of helical gears is extremely durable, plus it’s designed to use standard transmission oils.

This makes the Quaife ATB limited slip differential a genuine ‘fit and forget’ upgrade that offers compromise-free performance and unbeatable reliability on the street, strip, stage or circuit, backed by limited lifetime warranty.

Precision manufactured from certified steel billets and inspected to ISO9001-2008 standards, the key performance features of the Quaife ATB helical gear limited slip differential include:

• Safe, progressive and seamless in action, the Quaife ATB differential never ‘locks’
• Controlled power is transmitted to all driven wheels, to maximise traction and minimise wheelspin, particularly in slippery conditions
• Fitment greatly reduces unwanted torque steer, understeer or oversteer
• Designed to work in harmony with road car electronic stability and traction control programs
• Improves braking performance on front wheel drive cars by reducing lock up and minimising ABS intrusion due to torque transfer action
• Reduces tyre wear, especially on front wheel drive cars
• Gear operated with no service components to replace – ever
• Direct replacement for factory standard ‘open’ differential unit
• Retains normal axle lubrication systems and maintenance schedule
• Over 100,000 units sold worldwide since the 1980’s
• Backed by a Quaife lifetime warranty for both motorsport and road use