Axle breathers allow air to vent from the axle housing during heat cycles of the axle. It is important to relocate the axle breather to a higher location for the event of water crossings. If the breather is submerged underwater it can suck in water that can contaminate the oil.If you have the answer to the following question(s) please email them to: info@aftermarketbuildersguide.com – What is the thread pitch and size of the factory axle breather?