Twizwick Sprocketgrind is located in Mulgore on a high plateau only accessible through the Venture Co. Mine. The cave is full of level 8-9 mobs, so it's hard to reach him with a low-level character.
Enter the cave marked on the map below. Keep left, turn right over the first bridge, then left over the second bridge. There'll be an area with a few tents/camps and goblins. Past this, there are some trees, and around there is Twizwick. (61.8, 31.6)
/way Mulgore 61.8 31.6 Twizwick Sprocketgrind