I ended up beating him with Zer0.
Guns: Electric Infinity, Slagga, Conference Call, Norfleet
Relic: Blood of Seraph
Grenade: Homing Quasar
Shield: Alkaline Bee
Class Mod: Legendary
I use the Infinity to blast down his shield quickly while he is slagged from the Slagga. The Grenades are good on the enemies when you need to turn the wheel, and are electric so if Pete is near by it will group everything together and deal some damage to him.
I would pretty much just run around circles. Slag him from distance and Conference Call him til it wears off, rinse and repeat. When I needed to turn a wheel he was always on my ass, so I would go into Deception and hit him with the Kunai on the way by to the other side of the room where I would start the process over. The Norfleet was good for clearing out the mobs, and a cheesy second wind, when things got hectic. Sometimes it seemed like I was constantly fighting to survive rather than beat a boss, lol.