Ahh haah ahha lol . I have serviced lots of mud beaten 4x4 in Darwin and those sintered metal air/ stone like air noise suppressors wrongly used as diff breathers are notorious for blocking up with dried mud , especially when they are inside the heated engine bay . One bloke in particular had just about a gut full of another mechanic replacing 3 seals in his diff yoke and it was fine for a short time then leaked . After abusing the bloke and issuing a small claims notice to the other mechanic he ended up on my door stop . After placing a rubber tipped air gun used for testing automatic transmission seals during assembly was used we found the filter was blocked . 65 psi could not clear it so how could the diff heat expansion of gases vent . Once the breathers routed ino the airbox no more diff leaks even when you could not see what brand engine he had. The so called crappy plastic fuel filters you degrade have been in your cars you have driven for years and never let you down . Ryco make them . Don't tell me you have never driven a carby powered vehicle . The plastic fuel filters a better option for a vented breather for a lot of reasons and yes you do put the vent hole facing down just like your factory breathers to your front diff in your car come up and do a uturn and face the grown , You believe I suspect that your diffss done suck in water whne they cool down when infact they do suck water inform your filters every time they are fet and you turn your engine off , its only a little bit but it all adds up , when its plumbed into the air box the engine heat dries the air in the air box and when the engine is turned off your diffs draw in dry air . But if that's not for you and some people just cant seem to trust this system a plastic ryco fuel filter is 2nd best for the following reasons . 1 weight reduction as one filter does the whole 4x4 . 2 it prevents mud on the filter so doesn't block( and yes you have to install it with the opening facing down like all factory open extended breathers are ) . 3 it doesn't need a solid mount to stop it damaging your paint . simple zip ties work on the ome wire harness. 4 its a low pressure free flowing filter . 5 doesn't fall apart with extreme vibration and engine heat . The best is still plumed in the air box and if one was worried about tearing a breather hose and drawing dust into the engine you use a ryco carby fuel filter inline near the air box. Its always entirely up to you what you do with your own car and also what you do with information your read so I don't expect argument . You have the right to data dump everything here . I commented on this thread because thread because too many people are making very big dollars on diff breathing kits that do more damage than good because the filter element is exposed to the elements. I am just trying on this forum to help people save money and reduce possible early unforseen repair bills.Been using the pneumatic silencers for 30 years. Never had one block yet. Most aftermarket breather kits use them too. Depends where you mount them. Think you are getting excited about a non-existent problem.
Mounting position is just as important with the crappy little paper fuel filters you recommend. Mount them in the wrong spot and they will fill with water and act as a reservoir to allow water to suck back down the breather line as the diff cools.