A regular differential allows power to be distributed to the easiest to spin end of the differential. This means that when power is applied, it will try to escape via the easiest wheel to spin (in front or rear diffs) or the easiest set of wheels (front or rear) to spin in the case of the center diff. This is combatted by filling the differential with thick silicone fluid to adjust how equally power is distributed. Too thick of fluid will not allow the wheels to spin independently of each other for proper braking and cornering, too thin of fluid will not allow for power to be sent to wheels with most traction.

A TORque SENsing (TORSEN) differential uses a complex design involving straight cut gears and spiral cut (worm) gears. Using a certain mechanical property of the mesh between straight cut and worm gears, the TORSEN diff works in the opposite fashion of a conventional diff. That is to say it applies power to the most difficult to spin end of the differential when power is applied to it. This means the end with the most traction is the end that receives the most power. Also, the design allows the wheels to easily spin independent of each other when off power because it does not use thick silicone fluids. On smooth and/or high traction surfaces this design works great. However, it fails when you are on a rough or slick surface because the differential is constantly switching which end receives power, causing erratic handling, particularly when located in the rear diff position.

NOTE: These diffs operate on a mechanical property, which is not affected by changing the thickness of the fluid used. It is recommended that you use TORSEN specific grease (not silicone oil) and only in minimal amounts (just enough to lubricate).