The distinction centers on how a transfer case, a critical component in four-wheel-drive vehicles responsible for distributing power to both the front and rear axles, is connected to the transmission. In a “married” configuration, the transfer case is directly bolted to the rear of the transmission, forming a single, integrated unit. Conversely, a “divorced” configuration sees the transfer case mounted separately from the transmission, typically connected via a short driveshaft. A common example of the latter can be found in older vehicles where frame constraints necessitated spatial separation of drivetrain components.
This design choice has significant implications for vehicle design, maintenance, and overall performance. Married transfer cases generally offer a more compact and lightweight solution, contributing to improved fuel efficiency and packaging. Historically, divorced transfer cases were more prevalent in older, larger vehicles due to their flexibility in accommodating various chassis lengths and engine placements. They also simplified maintenance in some instances, as removal of one component didn’t necessarily require removal of the other. The benefits extend to accommodating a wider range of vehicle designs where drivetrain components cannot be easily packaged together.