You don't have a limited-slip front diff. Mud is pretty slippery stuff, and you may have even been high-centered. Chances are that neither of your front tires had sufficient grip, or the opposite front tire lost enough traction momentarily to let the driver's tire fling mud into your truck. :p

People usually don't get "new" LSDs. They either replace their open rear diffs or they modify their current LSDs by adding an extra clutch plate so they have more traction.

Contact Calmini (www.purenissan.com) for front LSD availability if you want more front-axle traction.