Unlike the "body-on-frame" Wagoneer, the XJ combined the frame and body into one unit. This made it 1,200 pounds lighter and much more rigid.
The Jeep Cherokee XJ, launched in 1984, wasn't just a new car—it was the blueprint for the modern SUV. Before the XJ, "four-wheel drive" usually meant a heavy, truck-based frame. Jeep changed the game by introducing a lightweight, unibody design that handled like a car but climbed like a mountain goat. The Birth of a Legend: The 1984 Jeep Cherokee XJ
Compare the to later models (like the 1997-2001 refresh)
It used a unique live-axle front suspension with coil springs, offering a smooth highway ride without sacrificing off-road articulation.