Time for some enligtenment.
First, If you do not know and understand fully how an open aka conventional diff works. Go here and learn it:
http://auto.howstuffworks.com/differential2.htm
I tend to go into too much detail, so if you have A.D.D. you might want to skip ahead to the
summary at the bottom.
Torsen AND Open Diff's:
--Spin both rear wheels in opposite directions with the input shaft(pinion) stationary.
--If you try "test 2" and have the pinion spinning (jack up off the ground all four wheels and let idle in first gear), hold one wheel still, the other spins double speed of the pinion.
--If you resist the 2X spinning wheel, the stationary wheel you are holding will begin to have torque transfered to it and will start moving.
Now, the difference is indistinguishable. They both perform the EXACT same way in standard operating conditions. The difference lies in this; Open diff's supply torque to the wheel with the
least traction, whereas Torsen diff's
transfer torque over to the wheel with the
most traction. However there is an exception, if on the Torsen set up a wheel has 0 traction, it is rendered useless and becomes a completely open diff unable to transer torque to the wheel with traction.
Test #2 tells you, you have a differential, it doesnt help with determining Torsen or Open. While doing the test, what WOULD indicate this however would be if you could actually measure the torque on each rear wheel at any given time and compare them side to side where you would see the torque split occur and which wheel it goes to.
Open diff's transfer the torque evenly, always. Straight line on perfect dry pavement each side of the rear wheels has 25% of the total engine torque, remember we are AWD and 25% to each wheel = 100% at the engine. If one wheel is on dry pavement, the other on wet the coefficient of friction is different. Now the wet wheel might spin a bit here and there, leaving the diff with 10% torque on the DRY wheel, and the remaining 40% on the wet wheel, because open diffs transmit power to the wheel with
least traction.
Torsen diff's transer the torque depending on its gear ratio torque bias. Once again straight line with perfect traction both rear wheels have 25% traction. If we have the same scenario with one wheel dry, one wheel wet, and the wet one having a small ammount of wheel spin, the torque to each wheel changes. Torsen transfers the torque away from the wet, spinning wheel to the dry, grippy wheel depending on its torque bias. If it was a 5:1 torque bias, the dry wheel now gains 40% torque, and the wet spinning wheel gets 10% of the torque.
NOW, if thats explained properly (god I hope so and I hope you all gain something from that and I didnt totally waste my time) then I will summarize my results:
SUMMARY
--Test # 2 gives you no indication whatsoever of what diff you have.
--Pulling the drain plug on the bottom of the diff and shining a pen light up inside and being able to see the worm gear/wheel sets gives you an indisbutable result.
--Without being able to test the torque acting on each wheel, visual inspection is the best way to determine if you have a Torsen or not.
That said, I found out I do have a Torsen, and I'm quite happy with that. Questions? Comments? Concerns? Complaints?