Triton - breath of fresh air, where?


New Member
G'day all, I'm hoping someone can give me some answers here. Took delivery of a new Triton GLS a couple of months ago, done a little under 4000 km already and am totally happy with it. I am particularly impressed with the features of this 'middle of the range' vehicle, with its 'Super Select 11' and locking diff it is pretty competent straight off the shelf. I have done very few mods, helper springs in the back for the caravan, obviously a bull bar and of course a set of drawers in the back under an ARB canopy.
The Triton is my forth fourby. And this brings up a question I'd like to get answered. All previous fourbies have had extended breather tubes installed from both differentials and transmission leading up to either a higher location or up to the engine compartment. The Triton does have an excellent breather rubber tube culminating in a metal tube with a breather cap on top ending up high in the engine compartment from both the front diff and transmission but not from the rear diff...on here there is just a domed plug...the screen shot below is taken from the workshop manual, I can find no other reference to it.


From experience I know that many a diff has been ruined when water enters and emulsifies with the oil, dunking a hot diff into a cold creek crossing is a sure way of doing it, the sudden drop in oil temp can cause a pressure variation and water can get sucked in, commonly via the outer seals, hence the installation of a breather with its opening above the water line.
I have been trying to find out more info about this thing on the Triton rear diff, my Mitsubishi dealership confirms that this device is a breather for the diff but cannot enlighten me on how exactly it works...will it allow water to enter?, they don't know. Next I emailed Mitsubishi's Australia's Head Office in SA, they too confirmed it as being a breather but they simply steered me to the User Manual where it states "...if the vehicle is driven through water it should be taken to a Mitsubishi dealership for inspection' Not particularly helpful. Finally I located an email address for the Mitsubishi factory in Thailand and asked them...that was 3 weeks ago, no reply.
So, I'm hoping someone on here has some info, what is this thing?, does it stop water entry or should I simply remove it and install a separate breather and tubing?

Lockyer Valley


Well-Known Member
Its what just about every old school 2WD has on the rear diff.
It will vent and equalise pressure without sucking in too much dust and water, but the little cap seal thing inside won't make a perfect seal if dunked in water and can suck water in.
If it does make a perfect seal, then you run the risk of sucking water past the oil seals, both aren't a good result.

If you get a screw driver or pliers and take the cover and the cap off, then there is probably enough vent tube to clamp a hose onto and run it higher. Its what I did with my old Ford Courier.


Well-Known Member
Yes it’s a breather. Yes it will suck in and seal during a crossing. Water enters via the axle seals, not the diff breather. The diff breather closing is what creates the negative pressure. Putting the same head on a long tube achieves not much because negative pressure is still created. The idea is to use a filter on the extensions. We used inline fuel filters as ends. The cap will be tapped into the diff. Unscrew it and go get a male barb fitting with the same thread, then run a hose with a filter on the end to somewhere higher.


New Member
Thanks all, it does seem odd to me that Mitsubishi has gone to the trouble of installing breather tubes from the front diff and the transmission/transfer case up to properly fitted metal tubing's secured to the firewall, complete with caps, yet the rear diff gets nothing.
Of course all this is only relevant should I dunk the hot diff in cold water, I am now pre-warned.


Active Member
Would definitely recommend changing over to an old style hose breather. Water will suck past your axle seals and into your wheel bearings and they are a PITA to change (I've done both sides in my Triton). No amount of oil changes will save the bearings from water ingress.


New Member
Thanks, another question:, how is this breather secured into the diff housing?, I would expect it to be screwed in yet the image taken from the workshop manual (in my first posting above) shows no sign of a thread....anyone know?