Place the garlic, onion, oregano, cumin, chile pepper, salt, and pepper into a blender. Pour in the olive oil and vinegar. Puree until smooth. Spread this mixture all over the pork loin, and place into a slow cooker.
Cook on low until the pork is fork tender, 6 to 8 hours. (If you need to speed it up, you can substitute 1 hour at high for two of the hours on low. Do this at the beginning, though, not the end.)
When ready, cut the pork into chunks, or shred; garnish with lime wedges to serve.