Join Date: Feb 2009
Location: Northeastern BC
Not sure if this is what you've got in your F250 ...
If it's a Torsen style LSD, then there are no clutch packs. They use helical gears. In my truck, the diff sometimes makes that howl in the winter before it warms up, and that's just starting from a light or something. I believe this is fairly common sound for Torsens under the right conditions when they're trying to hook up.
One way to get a Torsen LSD to catch is by lightly applying the parking brake, so that you are giving some resistance to the wheel without traction. Try to avoid allowing the wheels to stop turning. If you have no traction at all, or really poor traction, the differential has a very hard time engaging the wheel that's spinning the most from a complete stop, unless you do the parking brake trick.
That may also work for other types of LSDs, but I'm not sure.
If Princess Auto were a real girl, I'd ask her to marry me.