This is the Quaife ATB Helical LSD differential. You may be thinking "I have all wheel drive, whats the point?" While awd is a big help, your car, with its transverse engine layout is really more of a fwd car with a backup pair of wheels in the rear that step in once you lose traction, and even then its only 50% of the available power. That means the front wheels are still doing all the work, especially when cornering. But there is more to it than that. Your car (like most) has an open differential. This means when you lose traction at one of the drive wheels, the traction control system has to kick in and apply a clutch plate to stop the spinning wheel so power can be delivered to one with traction. This is rough and abrupt abrupt, and most importantly power robbing way of getting this done. The worst part is it only works once you have already lost traction. A proper LSD will reduce wheelspin, reduce torque steer, and allow you to put more power to the ground while cornering, awd or not. 

A direct replacement for the standard Audi/VW open differential, the Quaife ATB Helical LSD differential relies on gears rather than clutch plates for its operation. That means it is much smoother in operation. The Quaife ATB Helical LSD differential never locks harshly with a set pre-load of wheel slip across the driven axle, like a conventional LSD. Rather, Quaife ATB Helical LSD differential automatically biases the torque away from the spinning wheel across the axle, to a constantly varying degree, and never locks.

The ATB Helical LSD differential has many benefits over a standard open differential, including maximising traction and minimizing wheelspin, eliminating torque steer and snatching in front wheel drive cars compared to conventional LSD units, and a maintenance-free design which retains the standard oil lubrication.

The Quaife ATB Helical LSD differential is proven in circuit and drag racing, rallying and road use, and is produced from Corus steel billets, and is CAD designed and CNC machined, then inspected to ISO 9001 standards.

Please double check with Quaife directly if you are unsure about your vehicle as this unit is not returnable!

quaifeamerica.com

This particular unit is brand new, has never been installed, and fits the following cars:

2000-2006 Audi TT quattro 6 speed manual transmission

2004 VW Golf R32 6 speed manual

1999-2005 Golf/GTI with 6 speed manual and all wheel drive (4motion)

1999-2005 Jetta with 6 speed manual and all wheel drive (4motion)