Diff breather

[Balgar]

Need to get a diff breather for my 60 series landcruiser. Found water got into the front diff front po. Fist question is do I need to replace the front diff? I would like to go 4x4 but mainly use the 4x4 for sand. I replace the diff oil and still works.

Second is do I just get breathers for the diffs only or get breathers for the diffs, gearbox and transfer case? I see simple to install the breathers for the diffs but do I need to move the engine to get to the breather points for transfer case and gear box?

 

[Joe_E]

Having water in front diff is no reason to replace the diff . Just change the gear oil every so often to flush the water out. But you are gonna have to run it in 4 wheel once in a while to get the gears turning and fresh oil in everything because they don't move in two wheel drive.

It has a breather hose on it or at least should on the driver side axle tube.

 

[Balgar]

Could I just lock one front wheel so the gears move when driving?

 

[Joe_E]

Just lock both and drive a few miles at a moderate speed. No big deal.
Do it until you get just gear oil when you pull the plug.
Good idea to buy a five gallon bucket of 80W90 to save some money.

 

[Randy88FJ62]

You have breathers on both axles. I know I have one on my auto trany, I am not sure about the tcase but it must have one too?

You can lock your hubs and run the truck every once in awhile to keep things fresh and the seals lubricated. Runing your truck with locked hubs and not engaged in 4WD is safe at any speed. There can't be any binding unless you're in 4WD.

 

[lovetoski]

There are OEM axle breathers, but they often are clogged up. Ideal is to fab extended axle breathers. For the rear just run it up into the rear pillar. For the front run it up into the engine bay. You can add a VW (or similar) fuel filter onto the fuel line if you wish.

The transfer case has a breather also, very similar to the axle breathers. You can just reach it with your fingers up between the transfer case and the body floor. You can modify it like the axles, but will need to drop the tranny/transfer combo.

Tranmission "breather" is into the cab, through the shift tower.

 

[HJ61 12HT]

I'm extending my breathers at the moment, I'm going to use 8mm air line.
I wonder if anyone knows why they use a one way valve on the breather?
Surely it must cause air and dirt / water to be sucked in via the axle seals?

 

[jozlod]

As far as I know, the idea with the 1 way, is that any pressure in the diff, can vent out past the axle seals, and thats fine, as it wont take any water in, but you dont want it sucking in through the seals, as that will suck in water if you're doing a crossing or whatnot. Hence the one way, I read this somewhere randomly, can't remember where, makes some sense though.
Which way does your one way thing go? Hopefully it lets air in but not out.

I bought this kit, though it's shipped from aus. It seemed as cheap or cheaper as buying all the bits myself.

 

[ntsqd]

I don't think that I'd bother with a check valve or "one-way". You really don't want a vacuum in the axle housings, which is what will happen when a warm axle is plunged into a relatively cold stream/crick/river crossing. If anything you want a slight positive pressure to bolster the seals and push out anything that tries to make it's way past the seals.

A good filter on a breather hose mounted such that water isn't going to get into it is the better plan. I used to use the plastic inline fuel filters until a I built a baffled manifold with a single breather-filter. I've seen others plumb the breathers into the engine's air box. Want to be sure such is well baffled, don't need axle grease fumes causing detonation or run-on.

 

[Randy88FJ62]

I just disassembled my spare tcase and trany tonight there is a one way relief valve on the top of the tcase. I took it apart and there is a really light spring on top of a rubber disk. This breather valve must have a low cracking pressure close to atm as the spring force is close to nothing. I see very little risk for the average offroaders to get this clogged and prevent venting. The safe solution. Would be to take out the press fitted relief valve breather, tap the hole, and run a proper breather line. Many have done it on this forum with success.

 

[HJ61 12HT]

Which way does your one way thing go? Hopefully it lets air in but not out.
.

The valve lets excess pressure out, but doesn't let air in, so as the axle cools down it creates a vacume inside it.
Air has to leak in through the pinion & axle seals, this seems like a bad idea to me...

 

[Randy88FJ62]

The only releif valve on my FJ62 that I have found is the one on the tcase. It has a very light spring pressure so I assume that it lets air in and only closes shut under heavy external pressure such as a river crossing. The only negative thing I can see with the check valve is that it could get seized up with dirt, grit and muck and plug up. I think the safest and simplest way is to run a proper extended breatehr line up into the cab or engine bay.

 

[lovetoski]

The only releif valve on my FJ62 that I have found is the one on the tcase. It has a very light spring pressure so I assume that it lets air in and only closes shut under heavy external pressure such as a river crossing. The only negative thing I can see with the check valve is that it could get seized up with dirt, grit and muck and plug up. I think the safest and simplest way is to run a proper extended breatehr line up into the cab or engine bay.

There is one on each axle also. It's a small nob, sitting on top of the axle, just to one side of the diff.

 

[Randy88FJ62]

There is one on each axle also. It's a small nob, sitting on top of the axle, just to one side of the diff.

I know the axles, tcase, and trany, and distributor have breathers. I just looked and the axles have the same check valve as the tcase.

 

[jozlod]

... I've seen others plumb the breathers into the engine's air box. Want to be sure such is well baffled, don't need axle grease fumes causing detonation or run-on.

Wouldnt this create a vacuum? As the air rushes past/through the air box, it will create a vacuum in the line and the diff, I would not suggest this idea.

The valve lets excess pressure out, but doesn't let air in, so as the axle cools down it creates a vacume inside it.
Air has to leak in through the pinion & axle seals, this seems like a bad idea to me...

Yep, that doesnt sound the best, you don't really want that vacuum in there.

If you run the breather hose high enough above potential water, just chuck some kind of filter on it, and you should be pretty ok.

 

[Stumpalama]

It's pretty simple: Get a wad of 8mm or so vacuum hose a few T-fittings and some small zip ties. Remove the caps from the axle breathers, slip the hose over the nipple and secure with a ziptie. Run the hose along the brake line, securing with the zip ties toward the differential then use the soft brake line to run it up to the frame and leave some extra hose to connect to the hose coming from the rear.

For the trans/transfer I did the same thing (without removing either of them) using a T-fitting to join the hoses then fish a single hose over the transmission to the right frame rail and secure the the fuel line with zip ties. Now you can bring the hose from the rear diff breather forward by running it the same way as the front, using the soft brake line, to run it up to the frame and run it along the fuel line and T it to the trans/transfer hose and run it to the front hose from the front axle. Use a T to connect them and run the hose up the fire wall to the highest point you can. You can also run it into the cab if you like.

I used old brake bleeders I had laying around on the axles (they thread right in to the breather thread) and used one of the removed diff breathers at the top of the hose at the firewall to keep stuff out of the hose. I set this up 10 years ago and it's still working with no issues and I've done some deep crossings.
I did this for my FJ40, FJ62 and LX450.

HTH

 

[ntsqd]

I've seen others plumb the breathers into the engine's air box. Want to be sure such is well baffled, don't need axle grease fumes causing detonation or run-on.

Wouldnt this create a vacuum? As the air rushes past/through the air box, it will create a vacuum in the line and the diff, I would not suggest this idea.

The tiny vacuum present *just* inside of the engine's air filter would be so tiny as to not be worth considering. The vacuum generated by the cooling of a an axle housing that was just plunged into a cold stream/river/crick would far exceed it. At least I hope it would, an air filter that would have that much pressure drop is long, long past replacement or cleaning time.

 

[HJ61 12HT]

I've just had a thought, I could plumb the lines into the manifold after the turbo, then it will mostly have 10psi or so in the axles.
I wonder how much pressure it handles before spraying all the gear oil out?
More research needed...

 

[Stumpalama]

The valve lets excess pressure out, but doesn't let air in, so as the axle cools down it creates a vacume inside it.
Air has to leak in through the pinion & axle seals, this seems like a bad idea to me...

What makes you think the vacuum is sudden and strong enough to overcome that spring pressure? The little bobble cap keeps big crap from falling in the axle and does a less than OK job keeping water out during a water crossing that submerges the axle. Now, should the breather get plugged, then enough positive pressure will build up to a point where it pushes past the axle seal. Which is where you are more likely to end up if you introduce positive pressure into the axle housing.

I've just had a thought, I could plumb the lines into the manifold after the turbo, then it will mostly have 10psi or so in the axles.
I wonder how much pressure it handles before spraying all the gear oil out?
More research needed...

Why? If it is proven that positive pressure is what causes axle seal failure and subsequent gear oil-moly soup why would you introduce more? It is also proven that simply running a hose from the diff breather to a high point on the vehicle solves the issue, so why complicate it needlessly?

 

[lehiguy]

The stock setup has its limits and it's known to allow water in. I ran a vent hose from my rear axle (I tied it to the brake line) up along the frame rail, I spliced in both my trans and T-case to that line, spliced in the front diff breather and ran it up on the firewall as high as it could go. I topped it off with an in-line fuel filter and to that I attched a short piece of tubing facing down so gravity won't feed it crud as the years go by. Problem solved.