Axle Vents

[JohnnyBM931A2]

Did you happen to look at the price?

Ha.. Yeah I don't think most people are going to want to pay that for such an "unimportant" mod

 

[Capehenery]

I'm not very experienced with this Mod but why not install a single shut off valve and install a new or rebuilt axle relief valve in line with the shut off valve inside the cab. This would allow you to run the truck most of the time with the valve open and no pressure. When needed close the valve and the system should work as intended, since it was building pressure before the mod on its own. With the relief valve in the line inside of the cab it would be less apt to foul as quick and would prevent the axle from over pressurizing while in use.

 

[tobyS]

Ha.. Yeah I don't think most people are going to want to pay that for such an "unimportant" mod

It may be more important for a fire department in flood prone coastal areas than the average person. Or would seem like it should be. They are given the trucks.

 

[Artisan]

Yes I did.
But like I said, it was a quick look.
I am sure we could do a lot better if we found
the theory to be plausibly advantageous, if a guy can
say that................., well, I just did. !

Money SUCKS I know... Mcmaster is never the cheap guys
but you can find items and learn from their site.

Forget about the price of the regulator, what's the next hurdle?
Why is this idea a loser?

 

[Artisan]

Ha.. Yeah I don't think most people are going to want to pay that for such an "unimportant" mod

True, but trust me when I tell you more guys than
you can shake a stick at could care less about such
annoyances and simple want it, working, and "Yesterday".

Considering the alternative, which is what, tear into
things every time you ford?, it might be a $ saver.

I have never seen this idea of a super-low-pressurized axle
housing system before. Maybe there is a
huge NoNo reason why but till that is presented the idea is plausible.

If the NoNo is "It will leak a little bit of oil" I care not to hear that, so what.
If it leaks a LOT of oil it NEEDS to be fixed and not an issue.

Punt

 

[tobyS]

Why is this idea a loser?

Nobody says it is! But then it's a thread on a positive pressure fording modification.

 

[Artisan]

Well in a nut-shell what I mean is unless someone can
come up w/ reason why it is no-good, it is good.

 

[74M35A2]

I had pinion seals starting to leak on my M925A2. Removed all axle vents, confirmed they were clean and operating correctly, then changed over to open air vent tubes ran up the frame and such. Pinion leaks immediately stopped, and axles fluid level is correct. So, I presume the pinion seals are getting weak, but af least I could extend their life by relieving the small amount of pressure the factory spring loaded check valve allows to build.

 

[plode]

Reporting back. I couldn't get any decent pictures of any of it really...dark under the truck and bright outside was making for some terrible pictures.
The more I thought about running the vent line up the back of the intake stack, the more I thought about rain and condensation.
For now, I ran the vent line up into the battery box(under passenger seat) and put it right near the back vent hole. If I get water that deep, I've got more issues to worry about than axle vents.

(future planning--it would be a good spot to run an airline to, with a regulator and a valve mounted on the side of the box so I can turn it on/off without opening the box).

 

[Csm Davis]

True, but trust me when I tell you more guys than
you can shake a stick at could care less about such
annoyances and simple want it, working, and "Yesterday".

Considering the alternative, which is what, tear into
things every time you ford?, it might be a $ saver.

I have never seen this idea of a super-low-pressurized axle
housing system before. Maybe there is a
huge NoNo reason why but till that is presented the idea is plausible.

If the NoNo is "It will leak a little bit of oil" I care not to hear that, so what.
If it leaks a LOT of oil it NEEDS to be fixed and not an issue.

Punt

Okay most on here just need the open setup run to the intake, to stop the leaks. But for you other chuckle heads, like me, that think we have to have every bell and whistle look for the stock fording system that is made for your trucks, they are out there, the navy and Marines ordered most of thier trucks with the fording system which does just what y'all are talking about it adds a small amount of air pressure to the drivetrain. I have one on my M927.

 

[sandcobra164]

After all the flooding in my town, I'm thinking of going down this road as well. I'm curious if anyone can explain any possible ill effects with pressurizing the axles for short fording trips. I'd certainly not do it long term. I'd also like thoughts concerning pressurizing the trans and transfer case as well and removing the vent lines to the intake stack. My thought is to have a regulator and distribution manifold on the passenger side of the firewall that can be switched from vent to ford similar to the trucks factory equipped with a fording kit. I appreciate that it'd be simpler to find a truck in a junkyard that is equipped as such but I'm not so lucky. Does the factory kit pressurize the trans and transfer? Lastly, does anyone have experience using the fording kit in a real world mission? Would the outer seal leak enough to pressurize the hubs as well or would a tear down, clean and re-pack of the bearings still be in order. I'm leaning towards yes on that but still curious. Artisan pointed out that 0.5 psi of air pressure should protect a little over 4 feet of water from penetrating. Since I'm nowhere in the mechanical engineer field, I'm curious as to the math and reckoning involved. I had guesstimated that I'd need to run around 5 psi but I'd like to run only what's needed. I'm trying to save 36 quarts of gear oil in the event this flooding comes around again and I decide to help more.

 

[Artisan]

After all the flooding in my town, I'm thinking of going down this road as well. I'm curious if anyone can explain any possible ill effects with pressurizing the axles for short fording trips. snip

Look in the TM's for testing axles w/ pressure.
I am pretty sure it was the 5 ton TM I was digging in a few days
ago and I saw this. If correct, you can probably get a safe pressure
to run at. I doubt you will be able to pump it up to "X" pounds,
you will probably need a pressure regulator and constant air
to keep it a smidge above atmospheric pressure.

 

[sandcobra164]

I had planned on that. I figure it'll make bubbles but air going out should mean water is not coming in.

 

[vrshack]

One foot of water is about .43 psi. To over come 4 foot of water you would need more than 1.72 psi. Muddy water would have a higher specific gravity than clean water so the conversion to psi would be higher.

 

[vrshack]

To add to that, in 4 foot of water:

With less than 1.72 psi you would take in water.

With 1.72 psi you would not take in water. But no bubbles.

With greater than 1.72 psi you would begin to see bubbles. The more pressure the more bubbles.

We use a "bubbler system" to measure liquid levels in storage tanks. It works well but is a maintenance nightmare in some applications.

 

[sandcobra164]

vrshack,
Very informative sir!! Posts like that are why I love this site. I went and looked at a few M939 trucks with fording kits this morning. They look to only pressurize the power steering reservoir, transmission and transfer case. They also block off the engine crankcase vent. The axles though still have the regular vent caps common to all 5 tons and Deuces.