The heart of an off road 4x4 might be the engine but it's the transfer case that gets power to the axles! And with all the transfer cases out there, how do you know which is the right one for you? Jessi and Ian review the benefits of the most commonly used t-cases, their most popular upgrades, including some "doublers" and aftermarket cases too. Plus who will be crowned king of Mayhem Hill? Ian heads to Viola, Tennessee to find out in this one off rock race!