Hello, I was wondering if anyone could explain how a limited slip diff works?

I bought a 1996 f150 4x4 302 w/m5 trans. This is the first 4x4 I have owned, and I have recently started off roading. The other day I got stuck on(That's right ON not IN) a snow bank. The middle was solid ice so I bottomed out. I did get out on my own after some struggle (thank you limited slip).

On my way home I was hearing some noises, so I went back to work to check it out. While I had the truck in the air, I wanted to sea if my limited slip axles work. So I had it in 4 lo with the truck running and tried to stop each tire. I found that when I stoped a rear wheel it would start to chatter, but I could not stop the front tires.

This made me even more curious, becouse I was told that LS works with cyntrifical (tink i spelt it rite) clutces, and that they only engage when the diff starts spinning fast and that locks the axles together. But now I am even more confused seaing as how the truck was in 4 lo, 1st gear, and idleing (so it was very slow).

I have only rebuilt open diffs and just changed the oil on LS diffs (add the friction modifier).

So if any one can staighten this out for me I would really appreciate it. Other wise next spring I will tear out both diffs and fiqure it out the ol school way.
Thanks alot and sorry for the

 

It sounds like there is problem with the rear differential, you might want to remove the cover and check it out.

Here is a quick link to help explain the operaton of a clutch type diff.

HowStuffWorks "Clutch-type Limited Slip Differential"

 

thanks for the link. That did help alot.
Now that I understand it, I think you are right about my rear diff. I am wondering if the chattering is actually the clutches slippingl. If so they probably should not slip that easily, (I could stop a rear tire by hand). I am wondering if the clutches and/or the springs are worn out.

 

oh yea, this does not have anything to do with LS, but the noise I was hearing on my way home was the front axle U-joints (they are SHOT). I guess now since the list is so long I have no choice but to tear the front end apart. we got upper and lower ball joints, idler and pitman arms, brakes, rotors, and now axle u-joints. Yehhhhhhhh .

Thanks again for the help.