Axle and diff (?) breathers?

I've heard that to wade one needs axle and diff breathers. Why? What do they do? How do they work? What happens if you don't have them?

Cheers all.

axle breather's are diff breathers , and you already have them . they are the small pipes from the axle that appear in the engine bay , your gearbox has one as well . If you are going to go wading they need to be lengthened so they are out of waters reach , cable tied to the snorkel was always my favourite way .

yours should have them ,they are pipes that bolt to axle or gearbox and go to higher point in engine bay or chassis on rear axle,if you just had a hole on axle to breather water could enter if submersed,many are lengthened to deeper wading on axles

The breathers are to allow air to expand and contract as the axle heats or cools. If they were just on the axle as the hot axle was driven into water the air inside it would cool and contract sucking water in. That is the reason the pipes are fitted above wading height.

Ah, I see (I think). Thank you. So, it's to prevent water ingress? The main risk being rust? Or have I, in fact, not understood at all?

they have 2 purposes..to stop water ingress yes, AND to allow the axle to "breath"..otherwise as the oil and air in the axle heated up it would expand,crating a pressure build up that would force oil past oil seals on to brakes etc..
infact that is their MAIN job..BREATHERS THAT is

now real early rrc's just had a crude ball bearing type arrangement,no pipe..like a blow off valve with no spring..but these allowed water in when axle dipps below water..to stop this lr fitted pipes to the breathers,taking the open end above max recommended wade level..

whatever age yours is it has breathers..

(water ingress ****s the oil,****ed oil ****s the diff..)

its a zen says , but yours being a 2 door I think it may only have the ball valve on the axel cases and you may need to extend them up higher if you ever plan to go in more than a puddle as the ball valves dont work very well and you will end up having to change the axel oil if it gets water in.

for my 72 (which actually goes off road, unlike zens pose-master ) I was happy with the gearbox breathers as they came out on top of the engine but it only had the ball valves on the axels cases so I got a kit of ebay of loads plastic hose and come elbows which push in to the hole left in the axel case after taking out the ball valve.

ran the hose form there up higher, in my case front in to the engine bay and the back up to the fuel filler. hope this helps