Cases for or against extending transmission and trans-case breathers

[Clawhammer]

So I've been thinking that I need to extend the differential breather on my Tacoma's third member (take a hose from the stock breather location, run it up somewhere high in the fender or something, then add a two-way breather to the end of the hose). I get the rationale for this, that if the diff were warm, and I drove through cold water (which happens occasionally), that a vacuum could be created and water could be sucked in through the axles into the differential, and an elevated two way valve would prevent this.

(I think I understand that right - that water can't actually come in through the breather since it's a one way valve, and that it actually comes in through the axle seals or shafts instead. Can anyone confirm?)

While I was thinking about that, I thought that I should probably do the transmission and transfer case breathers as well. Then it occurred to me that there might not even be a path for water to get into the tranny and transfer case like there is for the rear end (assuming it's not coming in through the breather). Does anyone know for sure of have any other thoughts on the matter?

I'm wondering if I should just do the rear end and not worry about the others, but I'd hate to tear something up when that could have easily been prevented.

 

[Theoretician]

I think you answered your own question. It's easily preventable and you're down there extending the rear differential breather, why not do the transmission, transfer case, and front differential at the same time?

 

[Buddha.]

I should think with one way check valve scenary the water would come in through the seals on a trans same as an axle.

 

[dwh]

I've never seen a breather that was an actual checkvalve. Every one I've seen was just a tube with a metal cup over the end.

A one way valve would end up creating a vacuum in the housing as the thing cooled off.

Extend em all as high as possible. Someone makes a manifold for that. You bolt the manifold to the firewall and run all the breather hoses to that. Overkill, but there it is.

 

[Clawhammer]

I think you answered your own question. It's easily preventable and you're down there extending the rear differential breather, why not do the transmission, transfer case, and front differential at the same time?

Yeah, the problem is, while the diff is easy to get to, to access the trans case or tranny breathers I'd have to (near as I can tell) pull the console and boot from the shifter to access them. They're also a different style than the rear end. (To do the rear, you screw a fitting into the hole, and attach the hose. To do the trans, you have to take a little cap off with vise grips or similar and attach the hose with a clamp straight to the cast fitting. Somehow that just doesn't seem as secure to me). The third member also is lower than the others, so I figured it was the most susceptible.

 

[LocoCoyote]

It doesn't answer your questions, but it is a kind of neat aside point.... Did you know that UniMogs actually pump air into the diffs, etc to create a slight over pressure condition to keep water out during fording Ops.....

 

[dwh]

It doesn't answer your questions, but it is a kind of neat aside point.... Did you know that UniMogs actually pump air into the diffs, etc to create a slight over pressure condition to keep water out during fording Ops.....

Guy with a firemog says his doesn't have that. Says it's a milspec thing. Darrin Fink added a manually controlled valve to his so he could only turn it on when needed...something about blown axle seals.

 

[LocoCoyote]

Guy with a firemog says his doesn't have that. Says it's a milspec thing. Darrin Fink added a manually controlled valve to his so he could only turn it on when needed...something about blown axle seals.

Yes, that would make sense...and you are right about needing to modify it to be able to turn on and off. Seems that it turns on whenever you engage the locks....and it will blow seals.

 

[Mr. Snappy]

Slee off-road has breather extenders.

 

[overland_tennessee]

I actually made a video regarding breathers. I personally think, the higher the better.

youtube.com/watch?v=TAE1roaKpQg

 

[DanCooper]

ARB makes a $40 kit. I put one on my Outback for the shallow stream crossings I do. Google ARB 170112 Differential Axle Breather.

 

[Climberclimb]

Tacoma world has some threads on this very topic. Check under the hood - My 2015 looks to have two extended lines already. I cannot remember which they are for though! Must revisit that very topic!!
Cheers

 

[Clawhammer]

Tacoma world has some threads on this very topic. Check under the hood - My 2015 looks to have two extended lines already. I cannot remember which they are for though! Must revisit that very topic!!
Cheers

Front differential and some (4wd maybe?) actuator, I believe. Why Toyota did those and none of the others, I can't imagine.

It's trickier than I thought getting to the transmission and transfer case breathers. I can't even see them (at least I don't think so) from underneath. I thought I could get to them from the cab based on pictures I've seen, but apparently those pics were all manuals and I have the automatic which changes things.

 

[Madbodhi]

Big fan of overkill. Extending the breathers can be done very cheaply and is good insurance but it doesn't hurt to check your lube after playing in the water. No need for a fancy kit, I just used one because its pretty.

 

[Pilat]

A ridiculous point, but isn't a "two-way valve" just a hole?

Other than that, I agree with the others who said that you might as well do it all, rather than just some. If for nothing else than for peace of mind.