Diff Breather Routing - Pressure Issues?

Hey guys,

I have tried to search this issue, but I'm either a computer spastic, or asking a new question...

Regarding diff breathers, and the transmission, fuel tank etc...

Is it ok to run the plumbing into the snorkel? IE it would have a much higher port leaving more room for river crossings etc.

My thoughts are that it may have two problems, one - rain or moisture from the intake air, two - the venturi effect, run higher pressure air over an opening and the air in the opening, being lower pressure, gets sucked out, would this intake air be moving fast enough (remember turbo!) to pull the oils up and possibly out?

Thoughts??

Furthermore, I have seen the mathematical formulas for measuring the pressure, but don't have the tools to figure out the flow rate in the snorkel at the point of entry for the breathers... I understand the boost gauge may give an idea, but I think the actual flow rate at point of entry is what I'd need, over the whole rev range... phew...

Most diff breathers are run to the firewall in the engine bay.
I wouldn't be drilling holes in my snorkel to accommodate
any air lines. I used 6mm Teflon tubing with the quick connect fitting making sure it won't foul
on exhaust or other fittings at full stretch, terminating at a manifold with Air filter mufflers

the Engine bay should be fine mate, the suction effect during a water crossing will occur as it cools rapidly, this will be over fast and then it should not really be an issue. THe idea also is that if you do the river crossing with a crossing bra then the bow wave in front will keep the engine bay relatively dry and your breathers up out of the way.

Rear fire wall up the top should be fine.

Thanks guys, I thought the engine bay may fill up more than that! KISS principal applies!

Any good 4x4 shop should be able to sell you a f/r diff breather kit.
or like me source the parts and DIY, then you know its right .
Plus you save yourself some fitting $$$$$$s

I love the DIY idea three dogs! Not only is it cheaper, the sense of fulfilment is far greater than a shop bought kits ease!

Did my GQ and dads GU, got 20m of 6mmID rubber fuel hose, some clamps, a bit of sikflex, and some inline fuel filters. Mounted them at the back of the firewall, putting a loop at the top to hopefully act as an airlock should the need ever arise. Had some fuel hose left over, but it's a straight forward job. First car took a bit over an hour to work everything out. Second car was done in about 20 minutes.

This is something I'm going to have to look into as well. The GU that I'm buying is completely unmodified so has a bit of work to be done. Is the breather hole easy to find or is there somewhere that shows this kind of info on this forum already?

Very easy to find mate. They sit on top the diff and the rear one runs to a cross memberbut I cant remembrr where the front goes but you can do it for under 25$

TazManic, the GUs have breathers already run from front diff,transfer case,gearbox or auto etc run up to and end in the the front passenger guard and the rear diff breather
I think is just run into rear chassis rail. You can see the breather connections they are on high points and have 90 degree angle where breather hose connects.
I hope this helps
Cheers

Hi guys,

I'm looking at my diff breathers at the moment, albeit for a slightly different reason. I am starting to work on my dual battery installation. I have a problem where the metal fixed pipe on the passenger side near the firewall is preventing me fitting my ARB battery tray. From what I can tell, the metal pipe terminates under the passenger side guard. I haven't owned a car with diff breathers before this one, so I want to ask the question.

Based upon what I can find on this forum, I am under the impression that if I disconnect the hose from the fixed metal pipe where it joins above the chassis rail, and redirect flexible pipe to a breather can with an air filter on it, and then mount it on the firewall high up, this will allow my diffs to continue to breathe and function as normal.

Any problems with my planned changes that anyone with experience knows about? Any info would be appreciated.

15 years ago, I just woulda cut away and changed things without thinking about it...

Yes your making them redundant. Go for it. As long as you have a continuos pipe
Breather to the end those lines can be bypassed

Quote:

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Originally Posted by MudRunnerTD

Yes your making them redundant. Go for it. As long as you have a continuos pipe
Breather to the end those lines can be bypassed

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Cheers MudRunner, I'll pop down to the auto shop tomorrow for some pipe, can and filter. Any issues with volume, pressure rating of pipe, filter type, etc to worry about, or can I just take a new piece of flexible hose to a can, and then remove the metal fixed pipe?

Yeah any hose will do, it's only air. No pressure and very little flow. It is not uncommon for guys to fit a $2 inline fuel
Filter to the end as the filter to stop rubbish going down the hose. Fuel hose seems an expensive way to do it. Any rubber or plastic pneumatic type hose for the win. Have a look at the kit 3dogs posted for an idea of the type of hose. It will see No Heat, No Pressure, no Oil, Just Air flow.

I was looking at the breathers on mine the other day and it looks like the transfer case and gearbox are "tee-ed" together before they connect to the pipe that leads into the left front wheel arch
The other one there seems to be from the front diff.
Would it be fair to assume you simply extend those two connections up higher and then route a separate line up from the rear diff?
It is the rear diff that seems most vulnerable. Where the front diff is routed on a stock vehicle is pretty high as it is

Yes.
Many of the eBay kits forget the difference and transfer.
The gq runs front diff, gearbox and transfer into the front as you have found and realisticly are quite safe in there.
The rear is the biggest issue as that only vents into to chassis cross member.

I re did my breathers using 6mm teflon hose and those push fittings,
allowing plenty of room for full flex and avoiding exhaust .
Mine terminates up on the fire wall using a small air manifold
and brass air mufflers/filters. Plus plenty of cable ties
Link is for the brass filter
http://www.ebay.com.au/itm/140772721...84.m1423.l2648

I've got a similar hose to 3d (same stuff but mine is blue)and it has split at the connection on the rear diff, it's not a verry flexible hose from new and I think that's the issue

Quote:

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Originally Posted by MudRunnerTD

Yeah any hose will do, it's only air. No pressure and very little flow. It is not uncommon for guys to fit a $2 inline fuel
Filter to the end as the filter to stop rubbish going down the hose. Fuel hose seems an expensive way to do it. Any rubber or plastic pneumatic type hose for the win. Have a look at the kit 3dogs posted for an idea of the type of hose. It will see No Heat, No Pressure, no Oil, Just Air flow.

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Righto, it's off to Super cheap for me then, I'll try and remember to take a photo of what I chuck together and post it later, thanks again.