LSD question

[brendan1990]

Hey guys i was just changing the diff oil in my s2 after work today and one of my work mates came up to the car and asked "does it have lsd?" i replied "yeah it does" he then proceeded to spin the LHR wheel and watched as the other did not budge, now when spinning the tailshaft both wheels lock and spin at the same time but obviously not when spinning one of the rear wheels, so the guy doesnt actually believe i have lsd now, but im 100% sure that the s2000 does, now i work on subaru's all the time that have lsd's at work and when you spin one wheel the opposite one always does as well, so is the lsd in my s2 different from other car's, or is it loose? can someone please help me out.
He was spinning the wheel when all the diff fluid was drained if thats any help.

[ncmx5]

We do have a LSD. Stock s2000 uses Torsen LSD...Torque Sensing...

Was one wheel off the ground or both? Because the Torsen LSD can act as an open diff when one wheel is off the ground. I.e. When one wheel is spinning off the ground..the other wheel in contact with ground doesn't spin

[vyets]

Google Torsen LSD to understand what it is and how it works.

OR.... 2 seconds later..

http://www.s2ki.com/forums/index.php?showtopic=655223&st=0&#entry14935136

[euromandeluxe]

Torsen FTW.

i've done a lot of reading on LSDs and what not, but after all of it I still can't figure out whether the torsen should cause the non-spun wheel to turn when both wheels are jacked up and one is spun by hand. my understanding is that it acts like an open diff when not under load, but actively distributes torque mechanically (through the gears etc) when under acceleration and with asymmetrical traction. should it cause the non-spun wheel to spin like the clutch/viscous type LSDs do when both wheels are raised, or does it act like it's an open diff?

[YLDS2K]

The Torsen differential is a purely mechanical device; it has no electronics, clutches or viscous fluids.

The Torsen (Torque Sensing) works as an open differential when the amount of torque going to each wheel is equal. As soon as one wheel starts to lose traction, the difference in torque causes the gears in the Torsen differential to bind together. The design of the gears in the differential determines the torque bias ratio. For instance, if a particular Torsen differential is designed with a 5:1 bias ratio, it is capable of applying up to five times more torque to the wheel that has good traction.

In the case of both wheels spinning off the ground are usually found on all wheel drive systems (like the subaru's you work on) and also off road vehicle's such as 4x4's which is called a locking differential (wog term is spool) which the s2000 is not equiped with. This type of differential has the same parts as an open differential, but adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together. This mechanism is usually activated manually by switch, (lock hubs) and when activated, both wheels will spin at the same speed. If one wheel ends up off the ground, the other wheel won't know or care. Both wheels will continue to spin at the same speed as if nothing had changed.

Help this gives you an insight to the differences, put your argument with your mate to an end and gets me some rep points as i WANT TO BE A MEMBER lol worth a try

[vyets]

LOL howstuffworks.com :P but yea spot on pretty much.

The term spool you mean is purely a welded diff which is different from a "locking diff" no car comes with a spool standard because it's too rough to drive daily. Ever see them cars that just drive normally but their wheels shudder, and they leave tyre marks from just turning slowly that's because they have a welded diff, or a 1.5/2way LSD.

I'll give you rep points for a good effort at least you did the research :thumbsup:

[brendan1990]

ok thanks guys this feedback has been great =) ill have to quiz some of the guys at work now to see how they think the suby lsd's function

[ludecrs]

I imagine the Subi has something to do with its symmetrical AWD driveline?

[brendan1990]

i doubt it, symmetrical awd isnt as good as it sounds, its just slightly more balanced out compared to other awd systems, i dont see how it would effect the lsd.