Just as you need fluid in the form of water, the Jeep needs fluids as well. It is a good idea to take extras with you—at the minimum, take engine oil, ATF, and gear oil. The ATF can double as power steering fluid in a pinch, and all chain-driven T-cases require ATF. A couple of quarts of gear oil will cover either pumpkin; the manual transmission and engine are the most important components you have, so being able to refill if you need to is important. If you have the space, a spare oil filter won’t hurt; it’s very hard to get a punctured oil filter to stop leaking.