Diff Breather Idea

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Jul 7, 2005
I was reading the various threads about diff breathers, vaccum of air thru the birfs into the diff when it gets hot, and diff extensions. I was wondering if anyone had tried to drill/tap a second breather opening, and run tubing up into the engine compartment. Use two one way valve things (havent figured that part out yet.....one allowing air in, the other allowing air out. Theorhetically would create a draft of air thru the diffs, eliminating the vaccum. Might also keep the diffs a touch cooler(although underhood air isnt that cold).

Lookin for input on this. Do you guys think this is worth doin, or would the smell of hot gear oil (the only auto smell I absolutely cant stand) not be worth the effort?

I'll be doing a birf job on my lx in the next couple of months(work/travel schedule permitting), and may take the chance and crack open the pumpkin and drill/tap it.
Ok I'll go. In theory, that would probably work. but a lot of effort on your part. Most guys will just ditch (or modify) the breather valve, so there is free flowing air going back into the diff after they've extended the breather lines. I've seen many use fuel filters- just something to keep dirt out of there, but still allow air to flow back in. That solves the vacuum problem, and putting it up nice and high takes care of the water risk. hth..
not worth the trouble IMNSHO...
Too much, all that is needed is to delete the evil OEM flapper valve and the vacuum is gone,

Wile you are in there extending the lines higher and putting a filter on the end is a good idea. I routed all 4 of mine together to one point, after a recent thread I am thinking about doing the locker actuators also,

for the long runs steel line is cheaper than hose, just need hose at the ends to take up for movement

You will not get a constant draft through the diff with your proposed setup; it will exhale once out one valve during warm up and draw in once through the other when you park as it cools down,

Just make it easy no valves use the existing port for intake/exhaust
too much work better to use the powered variable altitude vent.:popcorn:
breather mod.jpg
On my H1 I had all vents were routed to the air cleaner. Including the intake for the CTIS. I think that's a great idea and will probably do it to my 80. I mentioned it once on here before. I don't know why it is not like that from the factory. I really don't see a better way of doing it. Of course the LC is not rated to drive through feet of water also...
When i get a chance, i'm going to put those ATV balloons on like woody suggested in the hardcore corner (i think it was in the hardcore corner). Keeps it simple and easy, while eliminating routing hose throughout the truck.
Not to be a party pooper, but running a checkvalve (what you were describing) is complicated, expensive, and will not cause the diffs to run cooler. Drilling and tapping means you've got to deal with metal files/chunks in your axle which you need to remove. Remove the 1/8 pipe thread fitting and install a nipple. Put a hose on and run the hose somewhere high...

stayalert said:
too much work better to use the powered variable altitude vent.:popcorn:

I think this is the best solution. A height proportional breather system.

Water gets deeper, just raise the antenna a bit more.

Thanks guys, it was just somethin that was crossin my mind...I definately need to sleep more... LOL

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