A differential / axle breather serves the important purpose on a 4WD vehicle of venting the air pressure in drivetrain assemblies such as the differentials, transmission and transfer case. Under normal operations, these assemblies heat up and the air inside expands, increasing the pressure and thus the need to be vented to atmosphere is created if a factory fitted breather gets blocked or jammed shut this pressure build up can cause the oil seals to blow out. When the drivetrain assembly cools down the air inside contracts and creates a vacuum.
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. The shortfall with the factory breathers is that driving through water crossings creates a vacuum caused by the drivetrain assembly being cooled rapidly by the water. This vacuum will tightly close the valve shut causing air to be instantly drawn into the assembly through the seals. Many times the seals are still submerged below water, leading to the water being drawn into the drivetrain. This will contaminate the oil and possibly damage drivetrain components or your Air Locker.
The AOB Differential Breather Kit is designed to eliminate these shortcomings by providing a high flow, zero back pressure, zero vacuum breather system. This is achieved with 4 high flow SINTERED air filters fitted in a central bracket that will allow up to four drivetrain assemblies to be vented to one central location, ideally somewhere on the vehicle that will be above the water level at all times. This kit is intended to replace your factory breathers and contains enough fittings and tubing to connect at least four drivetrain assemblies.
This kit is a 4 port system which includes fittings for front and rear diffs transfer case and gearbox to suit Toyota Tundra, Tacoma, 4Runner, Highlander, FJ Cruiser, Landcruiser and many others.
The kit comes with all the following items.
For a small investment they could save you many hundreds of dollars.