Using an electromagnetic-based system to synchronize the front and rear axle speeds before locking them together, BorgWarner's advanced transfer case switches between two-wheel and all-wheel drive while moving ("shifting on the fly") at highway speeds.Checked 2026-08-12
Transfer case
The unit behind the transmission that splits drive between the front and rear axles.
Also called: t-case · transfer box
What it means
Definition
The transfer case sits behind the transmission on a four-wheel-drive vehicle and sends power to both axles rather than one. Simple ones are selected by the driver through a lever or dial. Electronically controlled ones can change modes while moving — BorgWarner describes using an electromagnetic-based system to synchronize the front and rear axle speeds before locking them together, switching between two-wheel and all-wheel drive while moving at highway speeds.
Why a buyer cares
What it changes
It has its own fluid and its own failure modes, separate from the transmission. Whether four-wheel drive actually engages and disengages is something a test drive can establish.
In practice
Where you meet it
As the 2H/4H/4L selector inside, and as a separate case with its own drain and fill plugs underneath.
Two things that look alike
Not the same as
A differential splits power between two wheels on one axle; the transfer case splits it between axles.
Read next
Related terms
Where this comes from
Sources
A Chevrolet AutoTrac page was dropped in review — the sentence a research agent quoted is not on it.