DIY: Differential Breather Extension

god, reading that hurt my brain! lol...but I get what you are saying

 

One way valves don't let air (in our case) travel in both directions unless they are broken... Just sayin.

EDIT if you mean the breather has some resistance, I would understand then lol, but it doesn't seem to by looking at it.

 

axle breather mod questions

ok my breather is toast, the cap is crushed and bent, most likely because it appears the previous owner replaced the rear axle from a salvage yard because I see it has yellow numbers written on the housing.

I have to replace my breather so I was looking at the relocation mods but since I have a stock height regular 2wd, im not going to be running the hose way up inside the bed or to the fuel door as others do but rather I will just pin it up on top of the frame rail or to the underside of bed for added ground clearance to keep it clean and dry like on most 2wd trucks. I tow a boat so while I don't expect the axle going underwater you never know when it might get wet because shit happens at boat launches lol.

anywho here are my questions:

what is best type of breather - is it better to have a free flowing filter to allow air to go in or out as it wants, or is it better to have a factory breather cap that is a check valve and only lets air out and could, under the right conditions, form a vacuum in the housing?

which filter to use - assuming a free flowing regular filter is better should I use a paper element type air filter? or fuel filter? or one of those small metal screen filters used for lawn mowers? which is the best option and why?

fitting size - I see threads mention the breather is a british thread design and that is why you need to use a Toyota or Nissan fitting so the threads match but some threads say its 1/4" npt and give you a regular brass nipple to use so are they using the wrong fitting but the soft brass rethreads itself to the harder steel threads in the housing? what is the correct fitting to use because I do not just want something that you can make work?

hose clamps - lastly some kits have hose clamps and some don't but why? I realize there is little to no pressures involved to blow the hose off but shouldn't you always have a clamp on any hose connection?

 

I would question free breathing. Why'd they design it as a one way? I've read of some peeps finding tranny fluid at the end of their free breathing extensions.

 

anyone know where the breather for a 2003 is for the front diff? Read somewhere that I dont need to relocate it because it is already up high in the engine bay. but I couldnt find it. Pics would help.

 

Toyota did the right thing for the front differentials, the breather for it and the ADD are up high, near the battery (on the second gens).

The rear diff was a fail for any truck that goes into water over a foot deep. Instead of a breather, up high, they put a pressure relief valve on top of the diff. That is fine for venting expanding gasses, but does nothing to relieve the vacuum created when a hot diff is dropped into cool water, usually muddy water too! A true breather allows gasses out as well as clean air in if the pressure drops from sudden temperature changes. If you are in water, then water will get drawn into the differential through the axles.

Happened to my 2010 when it was 6 months old, changed the milky contaminated diff oil and then I performed this EASY mod... http://www.tacomaworld.com/forum/technical-chat/111954-my-differential-breather-mod-photos.html

 

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Is the valve that is supplied with this kit the two way or the one way valve??

 

Just looked at their link...

Wow, I don't like that they call it "check valve"... which usually means one way, like what is on the rear diff from the factory. That is of no benefit in preventing suction of water into the diff. You need a true breather, either a filter or the cap end that lets air both ways through, like Toyota puts on the front diff.

 

Yeah that's what I figured "check valve" meant as well. ONE WAY. So that's kinda disappointing if that's the case. Like you said there is no benefit there in preventing the suction of crap into the diff. Due to a vacuum situation.

 

Can anyone let me know where the breather for the transfer case and transmission are?

 

http://www.tacomaworld.com/forum/off-roading-trails/285498-two-way-diff-t-case-breather-mod.html

 

So I get the argument that Toyota made the rear diff breather a one way check valve for a reason, like stated above. BUT why in the hell did they utilize a free breather for the front diff?? Kinda blows the whole rear diff breather argument outta the water doesn't it?? There should be no reason why the front is free breathing and the rear a check valve...people say sometimes they get diff fluid at the end of their rear diff free breathing set up, well why isn't this a problem up front??

 

Awesome! Thanks Ferny and Tomtom

 

Np brotha

 

Just relocated my rear diff breather finally. Parts just been sitting in the glove compartment for over a week. Instead of moving it to the gas cap I moved it behind the driver tail lights. No drilling required. Awesome easy mod. now just got the T-case and tranmission to go.

 

Do u have a manual or automatic .... If it's a manual take off the shifter cover and boots and the breather is right on top for both the tranny and t case ..... How do u post pics with I phone

 

I have an automatic.
to post pics you just need to click on the attachment button "paper clip" and upload the pic you want to post.

 

ok, maybe no one knows the answers but i'll ask again

what is best type of breather - is it better to have a free flowing breather like used on the 4wd front differentials to allow air to go in or out as it wants, or is it better to have a rear differential breather cap that is a check valve and only lets air out and would, under the right conditions, form a vacuum in the housing to pull water in passed the seals?

I bought the breather #

$5 90930-03136 Toyota Breather Plug - 90930-03136

90930-03136 which has the check valve but it does allow "some" flow in both directions but the check valve will close with anything more then a very very gentle blowing in it. im just not sure if I should toss it in favor of the front breather without the check valve in it?

fitting size - I saw some threads mentioned the breather is a non standard special British thread design and that is why you need to use a Toyota or Nissan fitting so that the thread patterns match, but some mod kits for doing this say they use a brass 1/4" npt to hose bib fitting for the differential, so are they using the wrong fitting but the soft brass fitting just rethreads itself to the harder steel threads in the housing? I want to use the correct fitting because I do not just want something that you can "make" to work?

and a FYI about the kits you buy - some kits have hose clamps and some don't so make damn sure you always put the right sized hose clamp on any hose connection or the hose WILL pull off at some point just from normal suspension movement and hose flex. its always best to use the circular spring type clamps rather then screw clamps