Place pork tenderloin in a lightly greased crock pot.
In a small bowl, combine brown sugar, chili powder, paprika, salt and pepper. Sprinkle over the pork.
In another small bowl, stir together the minced garlic, pineapple juice and barbecue sauce. Pour over the pork. Cook on low for 6-8 hours, or until the meat shreds easily with a fork.
Shred the pork and serve on hamburger buns.Top with additional barbecue sauce and your favorite coleslaw, if desired.