ok try to stick with me now
ok, well hopefully you know that when turning a corner the out side wheel followsw a bigger radius!! well say you put a really thick oil in either front or rear. to all most make it solid, now both wheels will have to turn the same size radius / or not turn beacause the front is al most solid, normaly when going into a corner right all the weight is on the out side wheel. and the inner just sits there a bit, with not much weight at all. you make it a locker type diff it is going to stop the inner wheel from travling it's deisered path.. hence the wheels skip.

you only really need to watch a car going around a corner with a locked diff, and here it skipping.. i know this is taking it to the extreme..

the other day my friend had a locked diff in his mi2 on road, on a high grip surface, and he snapped a front dog bone becuase there was just to much load on the axle and the tyres had to much grip so the axle let go..

ok so now a normal diff works but putting all the power to the wheel in the air? say your cornering again, the out side wheel is hard on the ground and the inner is just touching, the surface, so you power on to get around the corner quicker, but all the power goes to the wheel in mid air?( not much point i hear you say.) and your right.. so now we put a thicker oil in the car(front for now) and we do the same thing, because of the friction in the heavey oil in the front) it makes the front axle more solid to speak, so you power on again around the corner, but this time more power it going to the wheel, that is in contact with the ground, because of that in creased friction in the front diff.


i hope you can sort of understand it now.. hope i didnt confuse you even more..
but there is a fine line with to much(heavey) oil in the front
and not enough.. beacuse of the los of power good luck hope i helped...