No, it's not *required* to break the transmission loose from the engine to drop the oil pan on a 2002 Dodge Ram 1500 with a 4.7L engine. The oil pan is generally accessible without separating the transmission and engine. However, it might make the job *easier* depending on your access and tools. Separating them gives you significantly more room to work.
In short: You can do it without separating them, but separating them might be preferable for some mechanics.
