My Differential Breather Mod Photos

Yep... easily... no hurry, no worry.

1) Drop the spare tire (and flip it so the valve stem points down, when done).

2) Drill the hole in the storage compartment (or where ever).

3) Remove the check valve (stock 'breather') and install the 'union' (with some wraps of teflon tape).

4) Route the tube from the union (secure with hose clamp) and cinch tie it so it doesn't hang... leave some slack to allow for axle travel.

5) Install the 'true' breather on the end and secure with hose clamp.

6) Raise the tire back up.

 

Hey, you want to work on a Baja race pit team??!!

 

I puttededed mine upinheeya...........on the 05 and now on the 08. Pic is of the 05.

 

What size threads is the union (#

$7 90404-51319 Toyota Genuine Parts - Union (90404-51319)

90404-51319)? Do you have to get it from Toyota? or an Auto Parts store? Thinkin, then that way you could reuse the Original Breather fitted into a insert barb, into the tube...

 

so i bought my hose line today. Went to pick up all the parts from the monkey dealership and the guy i order it from never order them Wtf. So i had to re order the union fitting, because they had the breather in stock. MAn i hate the dearlership geezes

 

i looked at the auto part stores. and could not find it. just get it from the dealer. i got both parts for $12.76 with tax.

 

x2

 

Yup, cheap!

 

I am not very technical and this may not be relevant at all, but I will share my experience with you. I recently sold a 98 Taco TRD that had nearly 380,000 miles on it. I bought the truck new. When it had about 25,000 miles on it, a guy checking the rear diff. lube showed me that it was muddy brown. It looked more like chocolate milk to me. I stopped by the dealer and picked up a new vent thinking mine was allowing moisture in. A local mechanic flushed the diff. with diesel fuel and filled it with fresh lube. A few months later, same thing again. This went on for the entire life of the truck. I got to a point where the lube was replaced every 25k miles. At about 250k I had the axle bearings replaced (not cheap) because of the bearing roar. Then at 300k I bought a used chunk (head) because of the bearing roar. The ring and pinion looked great but the bearings were all badly pitted.
The front diff. lube always looked good. I never did much off road driving and I am sure the diff. breather was never submerged. Not sure why I had the problem except for possible condensation.

 

sub

 

great write-up, thanks!

 

I have a few questions about breathers. I am a bit of a noob to all of this so please feel free to enlighten me...

1. The stock breather.... is it a spring loaded check valve that lets hot gases escape, but when things cool and contract it closes? Thats what one online video (selling a different type of breather) explained. By that logic, simply moving it won't solve the problem cause if it closes as things cool, water will get sucked in past the axle seals, no?? In that case it would make sense to change the breather to the type they were selling, which was basically an oil soaked sponge that allow constant exchange of air but kept water and contaminants out. If it is nothing more than an open hose with a cap on it to keep dirt and water falling from above out, then simply moving it higher up makes sense, in which case I am not sure why many of these tutorials list a new breather as a necessary part. Can't I just move the one that's already there?

2. I see under the hood there are two other breathers with hoses going to places I haven't bothered to trace yet. Can anyone spare me the effort and tell me what components these are breathers for? (yes, I am that lazy)

3. Are there others?? Front differential, transfer case, automatic transmission... Do I need to hunt them all down and re-locate all of them?

Thanks in advance for the help.

 

1. I think I agree with your logic about this. I heard about something called a polyethylene breather, but could not find them for sale. Either way, it makes sense to use a two-way breather if there is no chance it'll be submerged.

2. I'm pretty sure the two breathers under the hood are front diff and transmission. I think the transfer case may have one that stops short of where it should be, somewhere above the transmission maybe.

3. If you have the TRD OR model, you'll also have the rear locker. I recall reading that this either runs up to the sub-frame or is just like the rear diff. one was.

Hope this helps a little, but there is likely someone to fill in the things I may have missed.

 

I have the 2011 TRD 6spd Auto so no rear diff locker. Strange that toyota decided to put some breathers under the hood in relative safety but the rear differential has no hose at all.

The website with the interesting breathers is pirahna off road. Still wondering if the stock breathers do actually close under the right circumstance or if they are always open.

 

Piranha Off Road looks interesting, not sure if they sell to the US though.

I wasn't aware of a 6 speed auto. I thought the only six speed was the manual tranny. What TRD package do you have, the Off Road or Sport?

As for the stock breather on the diff, it has a spring under the metal cap that constantly pushes a valve closed. It may seem loose when you push down on the tin cap, but this is simply there to hold the spring against the valve. Any pressure within the diff will escape via this valve, but vacuum (pressure from the outside, will generally not bypass the valve.

 

Oops. I meant 5 spd auto. No diff locker anyways. So it sounds like the stock breathers are a one-way valve. Closed all the time and allow the diff to "breathe out" only. So what happens when it needs to "breathe in?" According to the Piranha Off Road guys, it sucks it in through the axle seals. So therefore, simply adding a hose and re-locating the breather is not going to prevent the possibility of getting water in the diff. I have seen a few forum posts that discuss using small fuel filters in place of the stock breather to accomplish the same thing as the Pirahna product.

 

Here is that Pirahna Off Road video

http://video.google.com/videoplay?docid=8973547597847260935&q=toyota+truck&hl=en#

 

Why not just use the parts that I did (that so many others here already did)... ? Just a few bucks at the dealer ($12?) for the correct breather and adapter/ union. It is the same breather that Toyota uses for the front differential... if it is good enough for the front, then it should be for the rear, yes?

The front differential and ADD breather are raised already... didn't I post photos of them?

 

Why not? Because if the Piranha guy knows what he is talking about (and maybe he's just trying to sell something that nobody needs) then the thinking is fundamentally flawed. How does the diff "breathe in" with a typical stock breather? He is saying it doesn't. That when things cool and contract and that stock breather is closed it sucks it in through the seals. its why many wheelers have gone to small inline fuel filters instead of the stock breather. Or am I (and others) totally misunderstanding how the stock breather works??

 

Update.... I just took the stock breather off my differential. The diff had been driven for 50-60 km of morning running around and then had been sitting for 30 mins or so cooling off. As I got to the end of the threads and I pulled the breather off, there was a "whoosh" and rush of air. Not sure if it was in or out but either way it goes to the point that the stock breathers are not really allowing the diff to breathe in and out. Its one or the other. When I blew on the breather it seemed to allow a bit of air to "squeak" through but when I sucked it seemed pretty air tight. Seems to support the position of the Pirahna guy doesn't it? They don't allow for breathing in and so there is a good chance that when you hit the water and things cool and contract, it could easily pull water in through the axle seals. Simply moving the breather higher wouldn't change this situation as potential for water to enter is not necessarily through the breather itself.