Although there are dozens of stock respirators and caps on the market are not fully effective are the EPT tests in all operating conditions. Variables, such as I / O speed, direction of rotation, oil level and viscosity worm drive and the mounting position affect the entire ventilation capacity.
In one way or another, allow all the flow of air respirators between the inside and outside of the transmission because the heat of the unit and cools at startup after shutdown. If the breather hose is exposed to oil splashes, oil bubble to form inside generally above the breathing hole, and escape from the hot air to the outside door. Over time, these small droplets accumulate until the device is visible "leak". If ventilation is completely shielded lubricating syringes inside the gear, almost all design will be effective. Unfortunately, this is usually the case, especially since most of the reduction gear box can be mounted in a plurality of positions.
A new design that uses a simple coil spring mounted in the vent of the air line, solves the problem. The interior of the spring has no continuous surface in which bubbles can form, thereby eliminating the effects of dripping and transfer of the resulting oil.