This Torsen Differential fits in the following applications: In the Rear Differential of: - ALL LADA Niva (VAZ 2121x) - ALL LADA Classic (VAZ 2101 - 2107) - FIAT 124 series up to '97 - ALL FIAT 128 series In the Front Differential of: - LADA Niva up until 01.2003                                 Torsen-type Automatic Torque Biasing Helical Differential This differential is best known under the name: "Torsen diff" The function of the Torsen Differential must not be confused with the "Limited Slip Differential" (LSD). The Torsen differential was originally invented for front wheel driven cars, where the LSD could not be used (because the LSD will make unwanted and dangerous jerks in the steering). The Torsen Automatic Torque Biasing senses which wheel has the better grip, and automatically biases the power to that wheel. It does this smoothly and constantly, and without ever completely removing power from the other wheel. Power is transferred automatically without the use of friction pads or plates seen in other limited-slip designs. Unlike a conventional plate-type limited slip unit, the Torsen unit relies on gears rather than clutch plates for its operation. That means, it is much smoother in operation because, unlike a conventional plate-type LSD, it never locks harshly when the Slip-Limit is reached. Rather, it automatically biases the torque away from the spinning wheel across the axle, in a constantly varying degree. The Torsen-ATB performs like a conventional (open) differential, until there is a loss of traction. Only then, will the torque transfer occur - when it is needed. PRELOAD This specific Torsen-ATB is furthermore equipped with a Preload (available in different torque settings (Preloads)). This is an extra feature added to this model. Look at the Preload-value this way: If one wheel is in the air, you normally loose traction. But if you were using the Torsen-ATB with the Preload feature, the wheel with contact to the ground would receive torque equal to the Preload-value. A higher Preload-value will: A lower Preload-value will: Lift the start-point you see in the diagram, giving more Torque at zero and low Traction. Increase the wear of the Preload-parts. Don't spin the wheels more than necessary when the Traction is < 10 %, and this will not be a problem. Lower the start-point you see in the diagram, giving less Torque at zero and low Traction Decrease the wear of the Preload-parts The prerequisites for the diagram are: Wheel number one, is always on solid ground. Traction = 0 % means, wheel number 2 is lifted off the ground Traction > 0 % and < 100 % means, wheel number 2 is on a slippery surface. Traction = 100 % means wheel number 2 also is on solid ground The diagram is not accurate, but shows only the proportions and tendencies Also, the diagram shows: a very low Preload-value for the Torsen a very high Preload-value for the LSD Also, you must remember that the LSD will change its characteristics as it gets worn. The Torsen does not. When the LSD gets worn, the green curve will move toward the red. When the Torsen gets worn, it's only the Preload that moves. The start-point (here at 10 %) will move down toward 0. The rest of the Purple curve remains unchanged. The parts that get worn are some spring-washers. Please note that, the Torsen curve is increasing dramatically if the Traction increases from 0 to 5 %. This is why you can use the following off-road-hint: Apply the hand-brake slightly if one of the rear wheels is off the ground. This will trigger the Torsen differential to believe there is a little bit of traction, resulting in 20 % more torque at the wheel on the ground. Select your Preload-value at the bottom of this page

When used in LADA Niva: The Torsen-ATB differentials require a certain amount of resistance at the ground (i.e. traction) in order to start the torque transfer. The Torsen-ATB differential will as minimum always transfer the Preloaded torque if the spinning wheel is off the ground or on an extreme slippery surface. If spinning occurs, often a slight application of the hand-brakes, while carefully applying power, will slow the spinning wheel enough to allow the ATB differential to transfer even more torque to the other wheel. In low traction situations, like snow and mud, the Torsen-ATB is known to perform very well. One of the biggest advantages this Torsen type is, that it is a 'fit and forget' design: You do not need to concentrate on when to lock and unlock, just drive and steer, the Torsen will fully automatically take control of the traction. Unlike a conventional plate-type LSD, the Torsen unit requires no special maintenance or rebuilds Is long-lasting since there are no plates or clutches to wear out Retains the standard method of lubrication - No special LSD-oil is required If speed/time is important, you would be better off, with a fully automatic solution like the Torsen-ATB The Torsen-ATB is used in luxury cars (and now available to LADA !) to improve safe driving in bad weather conditions This Torsen differential is made in Russia. The factory's main products are Torsen Differentials for VAZ, UAZ and GAZ. The factory also produces batches of LSD for VAZ. The factory holds the patent for this type of differential in Russia, and use only certified steel and staff in the production. The heat treatment of the gear-parts are also produced in batches and quality inspected before they are assembled. (Pictures from the factory will be available later) The picture shows the old LADA conventional (open) differential Replace item no. 2 with the Torsen differential Do not re-use the bolts (Part no. 1). New bolts are included. The new bolts have a shorter head since there is not enough space for the old ones We recommend using 2 new ball-bearings (parts no. 3) (Parts no. 5 - 9 are built into no. 2) Tip: The LADA Niva is just a Crossover (an ordinary car lifted and equipped with 4WD). It has NOT been reinforced in the drive-line. Installing a 100 % locker Differential requires careful driving to avoid broken axles/pinions/shafts/... The Torsen will never let peak-loads or short spikes pass through one axle, it will always be devided and biased through both axles. Required parts: Normal transmission oil must be used. Look for the text "GL5" or "GL4/GL5" on the back of the oil Locktite glue (or any other brand). ALL screws/bolts inside gearboxes/differential-cases MUST be glued. (Any mechanic knows this !) We recommend using 2 new ball-bearings (depictured above as part number 3)

Selecting the Preload-value How to decide, what Preload-value you need, depends on what you use your car for. (1 kg m = 9,8 Nm) LADA Niva LADA Classic and FIAT % Off-road or Race driving 0 - 30 % Front     Rear 4,5-6,0 kg m 4,5-6,0 kg m 30 - 100 % Front 3,5-5,0 kg m   Rear 6,0-8,0 kg m 5,0-7,0 kg m 100 %, Professional Front 4,0-5,0 kg m   Rear 6,0-8,5 kg m 5,0-7,0 kg m *** IMPORTANT, ATTENTION *** Please select your desired Preload-value below.