Hi!
I have few things to share with you about VC. I have tried to repair it twice for now :-). First time we have driled two holes on VC cover from the differential side. This was the same as the factory. If you take a look there is two factory holes which is shut with pins. We washed it whit petrol and 96% alcohol via air compresor and ocasinaly slowly spining VC. I have faund that WAG is using 100 000 cst silicone oil. This oil is near imposible to find in Serbia. Finaly found samethind that should be 100k cst, but probable was 60k or 90k cst. Volume of oil inside is only near to 40ml3. Its very small amount its mesaured with gasoline and syringe. Oil density wasn´t so big problem for poouring this time. Final result was that VC was transmiting same power, inaf to spin the rear wheel only when the one side of car is elvated in air but nothing that have any practiacal value. After much reding we concluded that the oil was to thin for YRV visco which is smaler in diametar and whit less plates than WAG (or many other). Opel Calibra (loth of power) visco is using 300 000 cst silicon oil. I have found same in England only 60ml3 botles, but that is enough. This time holes where drild in oposite sides (oil density is much bigger) one like time before and one on oposite side throw hole for bolt on VC for linkage to kardan (shaft). Pooring oil was quite dificult, in end poored about 33ml3, maybe it shoud be poored more (few ml3 more) but in literature a small amount of air should be a buffer for presure rising that would destroy VC. Result is that a VC is much stifer now. First test show that VC is working, but not locking. I´m waithing snow to see how much helpful should it be. It´s ímportant to mention that VC wasnt leaking or been sufered any visible demage before reparing. I could make same pictures of holes and used oil but am waithing to see how it will work.
Greetings from Serbia.