Diff Breathers

toyota has a metal cap then a spring then a rubber disc then the breather hole up thru the centre of it all. if that rubber has perished, the spring pushes the rubber disc to seal the hole so only air gets in, if you go thru water the spring tension applied to that disc should keep it sealed. mine hadn't after almost thirty years and i took it swimming up at moreton island, and the oil was as clear as when i changed it a week before.

oh by the way it would pay you to open it up and have a look, mine was filled with dirt but it was serviceable.

replaceing the original caps achieves pretty much the same as not having extensions at all. The idea of extensions is to allow the diff to suck air when it hits water at operating temp. The caps will shut off and the diffs will draw water past the wheel bearings anyway.

Well I never had water in my diffs so I geuss my set up worked ok

My apologies for trying to assist, carry on guessing. You'll recall MOST 4wd's don't have breather extensions and their setup works ok MOST of the time too.

Ooops, should read.
I reckon that before water gets into this tube.................

Scrubby.

It is both a function of depth and heat.

A beam axle, for example needs to be both hot, and partially submersed before it will try to draw water past the bearing seals.

As a general rule, anything over half wheel height is near enough to think twice before simply driving through. We've all driven through deeper water and got away with it, but at about half wheel height the driver should start to think about blinds etc - esp on the newer vehicles. Driving through at fording speed will generally not see any issues with breathers, it's when you have to stop midstream and 'change plans' that the seemingly shallow water can find you out.

Thanks GBC - good info, not having a mechanical background I'm learning fast! Figure we should be ok for our upcoming outback trip as the most we are likely to come across on our route is the odd creek to ford - but will definitely plan to fit some diff breathers before our next planned trip to Cape York. Thanks again, Cheers, Vin.

ARB???

Too right. They absolutely stuffed up some work for us. Cut a hole in the lining in the wrong place, mounted the wrong connector in it. Then instead of taking the wrong one out and putting the correct one in, the idiots cut another hole and did some very lousing to it. The wiring had to be replaced twice.

Anyway. ARB! What's so special about them. I would bet that most are NOT mechanics nor engineers anyway.

Phil