Any factory limited slip, otherwise called a locking diff, or a posi, should not squeel tires in a corner unless ur hard in the gas, there r clutches or springs in the diff that hold pressure on the side gears which turn ur axles, the pressure keeps the axles turning at the same speed, or locked. Each manufacturer has a set torque at which this lock is broken alowing for the tires to travel at different speeds in a turn so they dont squeel, wear out prematurely, or brake something. If ur axles r always locked i would open the diff, check for worn parts (spider gears and pinion pin r common for this symptom), if everything checks out, put in the proper fluid with a posi additive to ensure proper function, The spider gears and pinion pin wear together and can get stuck on eachother causing the diff to lock, i have broken a few from this same problem. i dont know however what the specs r on this diff. I have a standard open unit in my truck