breather tubes

[reg of the overflow]

some time ago, when "Thunderbird 2" was alive and well, I drove through a large puddle in the bush (the only one of the day I didn't check first) and consequently had water halfway up the doors...... :(


The diffs were fine as they had breather tubes but the gearbox resembled a cappachino machine when I got home. I want to seal the box up completely and put a breather tube in - has anyone done this - and successfully?


cheers

[Johnno1969]

Nope. But I'd like to. I'm all ears on this thread.

[reg of the overflow]

I'm not totally sure if all gearboxes are the same Johnno, but mine has a small plate on the top with a breather hole in it and the filler cap. Drilling and tapping a hole in the top plate seems easy enough but the problem to me seems to be how to seal the filler cap and still have it usable. Thoughts go to putting some sort of bush in there with a threaded cap if that makes sense.
Hopefully someone here will have an idea. I will continue to ponder. :/

[Johnno1969]

Can you post a photo of the area in question? By "filler cap", do you mean there's a dipstick on the box? Yeah, as far as I know,the wee pinhole in the plate pressed into the top of the box works as the breather. I would not think it too difficult to modify to a breather hose.

[reg of the overflow]

This isn't mine (too clean and not leaking) but it is the same. you can see the plate with the hole in it easily and the filler cap in front of it just behind the selectors

[Johnno1969]

Ah. Right. That looks like a pretty early one. My IIA's box is in the attached photo; at that spot it has a plate pressed into the top cover and a tiny breather hole.

[Ozdunc]

Reg, I would have though that the filler should be ok as long as the seal is good, as long as it doesnt sit underwater.
I would think you're only problem might come if the breather tube blocks for whatever reason and the filler cap is the only way for pressure to escape.
Not net but a wrap of duct tape over the filler would be and easy and effective way of keeping the filler cap in place.

Johnno, I've the same box as you. Hardest thing would be to remove the plate and refit with a decent seal. You wouldn't want to be tapping in place.

What about the transfer case?

[harry]

why not just drop the oil after getting home from a deep crossing.


while the box is hot the water will be boiled off, but if you got lots because you parked in the water for a while, drain it and put the oil back in without pouring the water back in back in.

[Ozdunc]

My gearbox doesn't get anywhere near hot enough to boil water. 45-50deg max according to my little infra-red thermometer (engine runs at around 80deg next to the extractors).

And you'd have to wait a while for emulsified mixture to separate wouldn't you?

I think if you know you're likely to get into a situation where water could get into your diffs, box and transfer extending your breathers would be the simplest thing to do long term.

[chazza]

Admittedly the S1 box is a little different to yours, but working on the premise that where oil escapes, water might get in, I sealed the following places on my 80".
1. Underneath the top-cover with a thin smear of silastic.
2. Underneath the plate referred to earlier, where the breather hole is.
3. The stack of shims at the back end of the transfer box, which adjust the pre-load on the bearing. I put Loctite 515 on the faces of each shim.
4. Check that the seals on the selector rods are in good condition.

Check also the front and rear shaft seals for weeping - if they are, they need replacing.

Getting the breather-valve off an axle and plumbing it into the hose extension would work well; have a hose for the transfer box as well and check the oil after wading even if you have fitted a breather,

Cheers Charlie

[reg of the overflow]

cheers all :)

[isuzurover]

I have extended breathers on my gearbox and t-case. I can take some pics if there is interest...

[Johnno1969]

I have extended breathers on my gearbox and t-case. I can take some pics if there is interest...

Yes please!

[isuzurover]

The tube starts at the gearbox breather (ignore the silicone it doesn't do anything), then T's in the t-case breather. The hose runs to a filter at the top of the firewall.



Ah. Right. That looks like a pretty early one. My IIA's box is in the attached photo; at that spot it has a plate pressed into the top cover and a tiny breather hole.

The round plate with the small hole is the gearbox breather. The square plate behind it (also with a hole) is the t-case breather.

[clubagreenie]

I used to do as above but drill it out and silver solder it in.