Originally Posted by Air Randy
This is absolutely, positively the sounds a lunchbox locker makes, and under the various conditions you describe.
The locker is basically two round metal pucks with large blocky teeth on them. Each of them is splined and fits over the end of one of your axles. There are springs in the unit that push these two pucks towards each other so the teeth mesh together thus locking the rear axles together.
The unit is designed so that whenever there is any torque from the drive train (i.e. in gear and moving forwards) applied it adds additional compression force in addition to the springs. Thats why if you have the drivetrain under load, even slightly, and you turn sharply on pavement, you may get a loud Bang! as the teeth of the locker disengage. It must either disengage, break an axle, or you would hear the outside tire screeching as it gets drug around the outside of the turn.
When there is no load on the drive train and you turn tightly on pavement, you will either here the teeth of the locker clicking as it disengages and ratchets, or it may be soft enough you dont even hear it. That is all pefectly normal for that type of locker.
The real benefit of this type of locker is they are inexpensive, easy to install and relatively reliable as long as you can put up with the torque steer and funky noises. They can also be a little scary driving on packed snow or ice when turning because you never know if/when they will disengage and give the back end a little twist. If you ever have to side hill off camber on a snowy icey area, you will wish you had a locker you could shut off.
The only way to get rid of the noises you are experiencing is to put in a air or electric operated locker. You can also install a locker like a Detroit Locker and it wont make the noises, but you cant shut it off either. Its almost as costly to put in a Detroit as to put in an ARB anyways.
This is a great description of how my Aussie locker behaves in the back of my 40.
Funny story - after wheeling the 40 for a day, I went to sleep and had a dream (I seldom remember what I dream about) that I was driving my little Honda Civic and I went into a turn and heard the front diff of the Civic clicking like a auto-locker/Aussie! I was totally confused in my dream, trying to figure out how the hell someone fit an auto-locker in the mighty Civic! Too funny. So that is one dream I remember.