My Differential Breather Mod Photos

I might be misunderstanding your post/issue, but I saw on the first page that David k already put a breather without a check valve on for his rear differential? Isn't that what you're saying should be done? Check out post #11, he seems to be saying the stock diff breather is a one-way check valve type and that the one he put on is a two-way breather without a valve.

 

Thanks Furb for pointing me to that. Guess I glossed over that the first time I skimmed through this post.

So I take it the Toyota part he ordered is a different type of breather than the stock one?? Looks pretty much identical other than it has a hose nipple instead of a threaded fitting. Guess I should see if my local dealer has one and test it myself. If it will allow air through both ways then I guess it will do the job. I would still be concerned if it got submerged as I can't see how it wouldn't suck water in. But I'm also not convinced that the Pirahna ones wouldn't pull in a bit too. I suppose that in the end, the best practice is probably to check and change the diff fluid as needed after deep water excursions.

 

David K is right. I just received the parts for mine today. The breather I ordered is in fact a two way breather (it has no check valve) where as the original one is a one way (out only). This would eliminate the possibility of sucking water in through the seals.

 

tbkfan- The two way breather will get water in it if submerged. More so than the original really since it is basically completely open. If you mount it in the fuel cubby hole and still submerge it though you will be cleaning water out of everywhere though. haha

 

Hello again my friends, yes you need to read my posts in this thread to see what I did...

The stock REAR breather is really an exhaust only, one way valve... Lets hot gasses out. It is spring closed and takes excess pressure to open out to atmosphere... Nothing gets into the diff. through IT (unless the spring and rubber seal is removed).

When you drive into a cool, muddy water crossing... if your diff. is HOT, contamination passing via the axle seals can (and did for me) happen.

What I (and others before me) did was put another FRONT breather ON THE REAR diff., but at the end of a tube, up above the water level. The FRONT differential has a simple two way breather which acts as a VACUUM BREAKER... If there is no vacuum in the diff. then water will not try to rush into it via the axle seals.

You can also put a breather filter (K&N or?) on the end of the tube or that Australian thing on the diff. itself. The whole point is to allow air to move BOTH direction (just like it does on the front diff.

This is one of the few FAILS from Toyota... to have a high 2 way breather on the front, but ignore the back (specially on Off Road TRDs).

 

just reminded me...
called toyota and my union and breather will be there in the morning. Luckily toyota already took care of the front and the front diff and TC are up nice and high. Will relocate my rear diff & locker breather to the gas door area this weekend

 

I guess the important point I missed in the initial discussion was that the new breather was a two way type. I assumed from the pictures that it was the same as the existing stock diff breather but with a hose nipple instead of a threaded fitting.

I considered the K&N option but to me it would have to be in a very dry location cause if it gets wet at all it could pull water in through it. Don't like that idea as I could see spray from rain/car wash getting the filter wet and allowing water into it.

I ordered the parts from Toyota today. While I am waiting for them to arrive I am going to pull the front diff breather off and do some experimentation. I am wondering how submersible they are. Seems to me that if they are mounted in an upright position, they may be more water proof than we are giving them credit for. Or at least for short dips anyways. I'm thinking diving bell effect here. Maybe I am wrong. Worth some experimentation anyways.

Either way, I should have just followed the initial post instructions but I have learned quite a bit about diff breathers here, so thanks to all who have participated.

 

It is just a cap on the end of the tube with very tiny gaps around to let air in or out of the tube/ diff.

Nothing magic going on.

 

Looks like a quick cheap way of getting added "insurance". My question is this....
Any issues with the new hose rubbing and possibly creating a leak along the frame or anywhere else it contacts a sharp edge of metal? Perhaps adding a rubber grommet to prevent this from happening?

 

Use 6' of 1/4" fuel line, that stuff is bomber tough!

 

Howdy fellow taco dudes. David K shows union part #

$7 90404-51026 Intake Air Control Valve Union

90404-51026, while Crom shows #

$8 90404-51319 Toyota Genuine Parts - Union (90404-51319)

90404-51319. Why the difference? Are they interchangeable?

 

As the others did, I left some slack in the hose for axle flex, off roading... It is thick rubber and not against anything sharp. However, nothing wrong with examining it from time to time.

 

Crom's looks the same as what I used... I show the package from Toyota on the first photos... you can see the part number.

 

I used David's part numbers when I ordered mine and I told the dealer how much they should cost based on David's cost and it was no problem.

 

Top thing is the 'union' that goes on the differential where the stock breather was. (-51319)

Bottom thing is the 2-way breather that also is used for the front differential. (-03136)

 

No, here is my photo from this thread's first page:

 

Ok. I'll go with David's part #s and cost. Thanks.

 

Great Job... Thanks for the info...

 

You are welcome...

I re-reading my procedures, I see I wasn't totally clear on how the contamination occurs. The stock breather is about 18" above ground, but when you go into water that deep, your axles are underwater first... and it is past the axle seals where muddy water can enter the diff. from a vacuum that a one way breather (the stock one) does not prevent.

Using the front style diff. breather mounted up higher, prevents a vacuum and thus there is no trend to suck water past the axle seals and into the diff. Water does not enter through the stock breather, unless it is defective because it is a spring loaded, one way, exhaust valve.

 

Being that I am from Canada I have concerns that in the cold winter months condensation would form inside of the "breather hose" subsequently freeze up and then not allow for proper flow. Does anyone else see this as a concern?