Not that it matters much, but I'm pretty sure the ring gear (aka differential case) is the input, the sun gear is output to the front, and the planet carrier is the output to the rear.
There are two clutch packs - the pilot clutch and the LSD clutch.
The pilot clutch is engaged by an electromagnet. This clutch basically clamps the input (diff. case) to the rear wheel output (planet carrier). The clamping force on that clutch pack varies with the current that the ECU sends to the magnet's coil. This current determines the variable 0-100% locked. *EDIT TO ADD: With any planetary gearset is you lock (or clamp with clutches) any two of the elements together (the ring gear and the planet carrier in this case), the gearset all tends to turn as one element.*
The LSD clutch is in between the planet carrier (rear output) and a plate splined to the sun gear (front output). There are three balls on the other side of the planer carrier in cam pockets between the armature and the planet carrier. When a front/back speed differential occurs these balls force the clutches together with a cam action (the planet carrier is actually forced up against the sun gear with the LSD clutches in between them). This is sort of a hybrid of a locking differential and a clutch differential.
If the front and rear are turning at the same speed there is no slippage in the clutches, as everything is rotating together. Only when the speed varies between the front and back do the clutches slip, and the relative speeds are usually small, so the slippage is small and the heat generated is small. If you are doing donuts, driving on icy patches, drag racing, etc. then things will start to heat up.
When the electromagnet is turned completely off this creates an open planetary differential. The 35/65 front/rear "torque split" is determined by the gearing in the planetary gearset. As an example if you were to lock the rear wheels with the parking brake, the front wheels would still put out 35% of the engine torque and eventually start to drag the back wheels. This has nothing to do with clutches and everything to do with planetary gearing which I studied the shit out of in 1986 thinking I was going to become some hotshot autmotive engineer.
