Differential breather lines

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I had a chance to look at the breather lines coming out of the PF differentials; the front diff breather line comes up to the back side of the engine air filter box and the rear diff line comes comes out along the frame behind the rear drivers side tire and turns down behind the fender. Both are completely open to atmosphere so every time the differentials cool down they can pull in a small amount of air and dust,...(and maybe why I'm seeing elevated silicon / dirt levels in my differential used oil samples). The rear line is in a particularly bad spot because if that area gets packed with mud or ice the breather tube could get plugged and one could blow some rear diff seals from pressure buildup.

Here's one guys idea of repositioning a rear diff breather tube on a Toyota, although some put it behind the rear light or even bring the line to the engine well;

http://4runners.org/writeups/typerdiff/index.html

The Toyota solution of installing a valve on the end of an extended breather tube is a good one as the built in flapper or ball valve keeps dust and water out of the diffs. A local Toyota parts guy tells me he sells dozens of the type 'N' valve pictured below, Toyota Breather Plug part number - # 90930-03136, mainly to non-Toyota buyers,...fairly cheap insurance for a $5 valve and a length of fuel line hose.



This bellows style breather cap on the end of the extension lines would be another solution;



http://www.trail-gear.com/diff-breather.html

Now I'm wondering what the transfer case and transmission have for a breather valve system.

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[Gray]

Here are a few threads from Titan forums with photos of how those guys install better differential breather systems to eliminate blown seals and dirt in the axles;

http://www.titanspot.com/Titan/index.php?showtopic=5666

http://www.titanspot.com/Titan/index.php?showtopic=3356

http://www.titantalk.com/forums/titan-f ... ution.html

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