Here’s an event that, like rare celestial movements and your brother paying back the money he owes you, only happens once every few decades: Mercedes is set to unveil a new version of the G-Class.

The squared-off brute is ready for its first set of major changes since it showed up as a civilian model way back in, uh, wow, 1979. Mercedes-Benz has chosen the North American International Auto Show in Detroit later this month to debut the new Gelandewagen, which is German for “able to climb over tall pointy rocks while still looking good at the country club.”

READ MORE: 2019 Mercedes G-Class Spy Shots Show More New Bits Headed for Production

Spy shots to date strongly indicate the new G-Class will retain its boxy shape, a figure that’s become a status symbol both on the trail and on the mean streets of Beverly Hills. Underneath the sheet metal, though, a bevy of changes are expected. Like most new iterations of automobiles, the new G is expected to be a lot lighter, with a weight reduction of about 350 pounds planned.

Despite the upgrades, purists needn’t worry about a wussification of the mighty G. It’ll remain a body-on-frame brute with a permanent four-wheel drive system and a live rear axle, though wager on a new independent front suspension that provides better handling and ride comfort.

The Gelandewagen is currently available in several different flavors, ranging from the G550 to the V12-powered AMG G65. Rumors persist of MB working on a new V12 to replace the existing unit that dates back to prehistoric times. However, a newfangled electrified version would not be wholly unexpected. Expect a couple of gasoline-burning V8 variants as well.

What began in 1972 with a collaboration agreement between the then Daimler-Benz AG and Steyr-Daimler-Puch in the Austrian city of Graz, is now a story peppered with superlatives and significant milestones. As it was back then, the current G-Class is still built largely by hand in Graz. The summer of 2017 saw the 300,000th G-Class roll off the assembly line

Mercedes recently released a teaser video of the new G-Class as part of its marketing campaign leading up to the big reveal in Detroit. We will have shoes on the ground at the show to bring you all the news of this and many other new models.