You need breathers because off the sudden temperature change when you hit water, sucks it in. I used to run cruisers back in OZ and always had water in the diffs even with breathjers. Saw the light and drive a nissan now, dffs, gearbox and tranmission free of water and they call me U-571 Al
Just a little tip, If you make the breathers higher ,DONT fit the little sprung loaded valves back on to the tubes, if you do you haven't done any improvement. Leave the ends open so the air can move in and out of the diff.
"Oldblue" Electric to Manual Hub Conversion's 03 5447586
If you want to get really carried away, Run all air lines (axles, transfer case's and gearbox) to a common manifold, and air pressurise it to about 4lbs. Most seals are pressuried to 7 -8 lbs so it shouldn't blow oil out them. The extra presseure should be enough to keep the water at bay. Works for me anyway.
Ugly is a state of mind..... and the state of my truck!
Stopped all the gravel and crap getting carried by the water into my diffs though!!
I've also fitted a breather to my transfer case. Water can get into this from the input shafts, which will suck/blow jut like your diffs when plunged into cold water.
theres a real easy way of fitting breathers ,
grab a threaded elbow from the "push fit" air fittings range .
these can be bought threaded on one end and will screw straight into the
diff housing and the air line tubing simply pushes into the other end .
Norgren , TWL , or other truck (real trucks) bits shops or tool shops .
Just hoping to save you time on your back under your wagon , means you have more time to plan the next mod for your surf