Rear Differential Breather Argument

Hey Guys, There are a lot of great write up's on this upgrade. I need your help with an argument I'm having with my buddy about the rear diff. breather relocation.

My 03 Tacoma has the OEM check valve breather, I going to relocate it inside the fuel fill door, but my friend is telling me it’s a waste of time.

His position is the OEM valve is a one way valve, why change it if not going to take in water? Just exhaust. Hence check valve. (Spring loaded) He is a big car guy, not Toyota but German vehicles and Muscle cars.

I'm not doing it to equalize the pressure in the diff, The main goal is for high water, mud ect. I don't care about the cost it's fairly a cheap mod, so what do you guys have so I can win this one.

I don't need the one it's your truck do what you want. This is solely on mechanics/gain of the upgrade.

 

Ok so the diff gets hot and vents air out because it expands right? Ask your friend what happens to that air when you submerse the axle in cold water? Well since you have a one way check valve it can't breath air back in, so instead it sucks in through the axle seals and since your axle is under water it will suck in the water. Follow the diff breather mod and ditch the one way valve, if you mount the one way in the fuel fill it will still happen because of the check valve

 

I've wheeled my Tacoma for 14 years with the stock set up.

I've been through several dozen creek crossings and even though I try to avoid mud, I've still been through lots of mud.

I've never had an issue

 

Thanks Jack, that’s a quality answerer I need, sometimes you need the technical for these old timers to validate the mod.

 

Tell your buddy he's full of shit, theres at least 10,000 tacoma diffs in Ca. alone that suck in water, it's a somewhat weak springed popit valve

 

I'm an old timer that needs no validation, its just common sense

 

I don't even think mine has a spring, the cap part just rattles around

 

Doug it's not who's full of it, it has to do with the mechanics/gain of the mod. There a lot of mods. out there that make no sense, or a waste of time. Just for show you know where I'm going with this.
This is not an old fashion Smack Down, just a friendly argument.

 

Oh, no worries I routinely tell my friends they're full of shit ....


But I get what you mean

 

Just for reference, that is not a one way valve on top of the axle. If you look, the front diff and a.d.d. have the same breather as well as the trans. and t-case. There is no way they would put a one way valve on something that needs to breath in and out. The way the cap is designed, the weight of water presses the cap and not allows it to suck water in, but then it sucks it through the seals. Regardless, it was stupid of toyota to put the breather right on top of the axle and put the front diff breather up high, under the hood.

 

03 it's a good easy mod to do. Toyota should have did it out of the gate, but you know they leave out the small things sometimes. What Jack said is spot on.

Once you win the argument, have your buddy do it for you as the payback.

 

Hypothetical:

You have the two-way breather (or whatever it's technical name is) the mod calls for behind the gas door.

Say you get into water higher than the breather (yes I know you'd have a lot more issues than your rear diff), then what?

 

Then you will need to change out your rear diff fluid along with the rest I guess. Unless you make a snorkel for it lol

 

Putting the diff breather next to the fuel cap (that also vents) Its hypothetical but just think if your diff breather was sucking in gas fumes venting from cap drawing the fumes into the diff, extremely hot days of summer, fumes expanding, finds a source of ignition with diff full of semi pressurized gas fumes.....


it'd never happen prolly, then again "never say never".. haha

 

Forget the diff mod...

I'm coming up with the inflatable pontoon mod!

 

Oh great, you just poked my OCD.

Then where would you suggest putting the rear diff breather?

 

It will be the same as having it on the axle, it will just suck water into the diff, one way or another. If I was to ever snorkel my truck, I would drill some holes in my snorkel and run the vents lines into it and silicone around the lines to seal the snorkel back up. That way the lines are vented as high as the intake.

 

If you don't have a snorkel then you can run it up under your hood so that it is the same height as the front ones. Don't forget to do the same thing to the trans. and t-case.

 

Honestly ?? Although I admit the location behind fuel door looks trick, it's kinda overkill , but thats just me, I found some hose that fit just snug enough to seal around the breather & just ran it up over the gas tank/frame..

Because as you stated earlier if water is above the relocated vent, you have waaaay bigger problems than a submerged vent..

 

Age: 55

Look at Gramps spittin' out the lingo