Rear diff breather mod, should I have already?

Yep thanks for the post, a nice birthday present for me as today is the day!

 

Your welcome and Happy Birthday

 

i went off this thread, http://www.tacomaworld.com/forum/2nd-gen-tacomas/286097-rear-diff-vent-behind-tail-light-mod.html but David K(thanks!) is credited for providing all the part numbers. i just preferred the vent behind my tail light. the union and two-way breather were $11.xx from the dealer. i haven't installed anything yet, but i have a mod weekend planned soon to put some of the parts i have been accumulating on the truck.

 

Thank you.

 

Thanks darkfader, I will mod in the same location as I am waiting on an order for my Tuffy lockbox and do not want to put the tube there.

 

no prob! i had to go to lowes for the rubber coated clamps in that writeup. everything else was on hand at the autozone besides the factory breather and union.

 

If it stuck open that would be good, then it would actually breathe. Of course if you go deeper than 18" water crossing is why a breather should be higher up.

The factory thing is a spring loaded vent that purges excess pressure. However, a breather would let the pressure equalize, preventing a vacuum from being created which is how water is drawn into the differential.

It happened to me when the truck was only 6 months old, the diff fluid was milky from water, and after that oil change I performed the mod. Never again a problem crossing muddy water!

 

Exactly...emphasis on it not being a breather from the factory, more of a suffocator. Regardless of water crossings or not, doing this will take pressure off the axle seals making them last longer. Putting the new breather that actually lets it breathe is primary and putting it up higher to keep water out of it is secondary because you will always build pressure on the seals driving far or fast enough to build up heat but you will not always be doing water crossings.

 

I suppose you could leave it open or screened but parts are cheap enough to just get the breather. When you have both in your hand you can tell the difference in the 2 by blowing/sucking (yes, I said it that way) on one at a time and see where the original is restrictive in one direction but the replacement breathes freely in both directions. Mine is terminated in the gas door area above the filler, some run theirs into the storage compartments or the cubby over the wheel well. None of these are technically sealed. Having it in a different sealed location would cause same issue as the original setup has. They are protected areas compared to it just being on top of the axle housing but not truly sealed. Not sure where you are going with the first comparison question in your last post........

 

The factory breather is a one way valve. It lets air out but not in.

When a hot axle with heated air gets dunked, the air within the axle cools, contracting and creates negative pressure (a vacuum). Air can not be sucked in through the factory breather due to its one way nature. Thus the only way for air to come in is through the seals at the pinion or end of the axle shafts, and when dunked instead of sucking in air, it sucks in water.

So even if you extended the line up tall, and used the factory breather tip, it would defeat the purpose. FYI water does not get in through the factory breather, like stated above it comes in through the seals due to negative pressure.

 

I am wondering if the same part numbers work on a 94 pickup. The 94 diff has a vent on it and not a high mounted tube with a breather.

 

this escalated quickly

 

Yes it did, I changed the oil today and it looked pretty good for 90g. No water residue at all. I think I'll leave it until I'm really bored some day.

Took a little less than 3 qts amsoil 75/90

 

Haha, now that you've said that it's destined to get fuggard!

 

Ain't that the truth.

 

[I see someone finally got through to you on this since I was last on this thread. My answer, just fyi:]

*The factory rear breather is the problem, not where it is located.
*It is not a breather, but a spring loaded vent.
*The mod uses the same breather Toyota uses on the front differential (a real breather).
*Being a real breather, it is located higher than any water crossing, at the end of a tube, just like the front one is.

 

Have a great day, and stay out of deep water until the mod!

 

The OE rear diff breather cap is actually not spring loaded, at least mine on my 06' sport lsd rear was not. I was curious about it when doing my mod and I popped the cap off and it was simply a loose cap held on by the small pinches in the cap.

 

Mine was... it stays closed unless pressure (inside the diff) pushed the valve open (held closed by a light tiny spring). The front and mod breather is a simple cap pinched to hold onto the adapter base... essentially just reducing the air flow way to minimize any junk getting in. Obviously a K&N or other brand breather filter would be awesome instead of the Toyota one.

 

Yes, I need details too... that's what brought me here in a big way, looking for an explanation on how the traction controls work! The dealer knew little, the manual said little, but TWers were very helpful... but, I had to continue the research and wrote many versions for TWers on how it works. Now, if there's an A-TRAC question, I am expected by some here to show up in those threads! LOL