Terminator03
New member
Yep, I ordered the union part too, but thanks for posting the part number to help others, especially for future searches.
Don't just relocate your stock diff breather. Mod it or you're not protected!!
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Yep, I ordered the union part too, but thanks for posting the part number to help others, especially for future searches.
4Reak Show
New member
Alright so it's time for me to hop on board. I had some thoughts regarding the issues the OP and ARB bring up. Disclaimer: I'm not a scientist/engineer/thermodynamisist/fluid flowologist
Claim is that the rubber flap in the stock breather makes it a one way valve and creates a vacuum. A vacuum is an airtight seal so there is negative pressure inside the axle housing. Once submerged the cooling draws water into the housing through the axle seals.
Issue I have with this theory is that water molecules are larger than air molecules. Therefore, if the axle housing holds an airtight vacuum, it will also be a water tight vacuum...
Reason I'm bringing it up is that I'm about to do mine and these breather plugs are terrible. Totally OEM and they just feel super cheap. I can actually rotate the cap to a sweet spot and get it to almost completely block airflow in either direction.
I also think Toyota engineers do their homework and have been running these rubber flap equipped one way valves for the better part of like 40 years now... I DO like the idea of having the valve being out of the way in case of mud or snow so I'm just moving the stock valve higher.
Claim is that the rubber flap in the stock breather makes it a one way valve and creates a vacuum. A vacuum is an airtight seal so there is negative pressure inside the axle housing. Once submerged the cooling draws water into the housing through the axle seals.
Issue I have with this theory is that water molecules are larger than air molecules. Therefore, if the axle housing holds an airtight vacuum, it will also be a water tight vacuum...
Reason I'm bringing it up is that I'm about to do mine and these breather plugs are terrible. Totally OEM and they just feel super cheap. I can actually rotate the cap to a sweet spot and get it to almost completely block airflow in either direction.
I also think Toyota engineers do their homework and have been running these rubber flap equipped one way valves for the better part of like 40 years now... I DO like the idea of having the valve being out of the way in case of mud or snow so I'm just moving the stock valve higher.
Lapooa_338
New member
I noticed you had a S Bend in your fuel line, I heard that here oil can condense and plug the line in cold conditions if enough gear oil is accumulated
toastyjosh
New member
Nice write up
I don’t think it creates a vacuum, I think it creates negative pressure due to temperature differentials and when you all the sudden dip into some cool water it sucks it in. People without doing the diff breather mod have submerged their rear diffs in water and later found their diff fluid tainted with it, meaning water got in somehow and a 2 way breather allows pressure relief to prevent this, and then the reason the breather gets extended is because of the 2 way new valve.
If you go on a nice long drive and then unscrew the breather you will hear a large whoosh of air.
Drcoffee
Senior Member
Have you seen gear oil gel enough to become solid? Me neither. It may thicken, but air will still be able to expand and contract. You need the hose long enough to move with the suspension, which means there will be a loop of hose above the differential.
rdruss
Senior Member
I, too, will side with Toyota engineers on this one, I would guess the vacuum created by sudden cooling of the rear diff doesn't create enough vacuum to compromise the seals.
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