Join our adventure community
Subscribe for exclusive tips and gear updates to elevate your outdoor experience.
A differential/axle breather serves the important purpose on a 4WD vehicle of venting the air pressure in drivetrain assemblies such as the differential, transmission and transfer cases. Many drivetrain assemblies are fitted with a breather from the factory. These factory breathers are usually a one-way valve mounted directly to the housing or remotely on a short tube.