Venting the front axle on CUTs(with pics)

[nmu98]

Apparently he had two leakage situations. If he's on a slope he still has to have higher pressure in the tranny to force the oil out IF the vent is below the oil line. I addressed this possibility with a collection chamber.
The problem when he was on flat ground could only happen if the vent was below the oil line so my thinking is that there were other problems with his design.

Again, we'll see what happens with my design, right now it's fine. I drove on slopes when it was cool and allowed the axle to heat up without incident. I think the oil sloshing around allowed enough air to keep the pressure neutralized.

What's your design? Got any pics?

Rob

My idea would be similar to yours but I would use a gearbox vent and cut it down so it can also be used as a dip stick. Then all I need is a simple bushing to go from the size of the metal gear box vent to the 3/4 10 threads of the axle. I posted pictures of the gear box vent I have in mind.

With that said, I will do nothing until these other issues are sorted out. I have never had a seal failure on any of my 3720's and I plan to see how much pressure the 4520 builds before I do something that could cause more harm than good.

I would love to see you guys get this working correctly. I know you feel you have it solved, but I feel your design lacks a few things I am looking for. I would also be a lot more interested in building something if I had my new tractor....

 

[Rob-D]

My idea would be similar to yours but I would use a gearbox vent and cut it down so it can also be used as a dip stick. Then all I need is a simple bushing to go from the size of the metal gear box vent to the 3/4 10 threads of the axle. I posted pictures of the gear box vent I have in mind.

With that said, I will do nothing until these other issues are sorted out. I have never had a seal failure on any of my 3720's and I plan to see how much pressure the 4520 builds before I do something that could cause more harm than good.

I would love to see you guys get this working correctly. I know you feel you have it solved, but I feel your design lacks a few things I am looking for. I would also be a lot more interested in building something if I had my new tractor....

What other issues? We know what happens and why it happens.
We don't know my design isn't "correct" and what few things are lacking? Can you please be more specific.

Rob

 

[Spudland_Dave]

I'm shoulder to shoulder with NMU here...

I Posted this in the "other" thread....Here is something else to think about....
http://www.tractorbynet.com/forums/john-deere-owning-operating/179279-more-leaking-axle-seals-vents-2.html#post2044115

NMU, when/if the time comes to do what we both are thinking..I got you covered....

 

[nmu98]

What other issues? We know what happens and why it happens.
We don't know my design isn't "correct" and what few things are lacking? Can you please be more specific.

Rob

The other issues:

After some use Arrabil has a puking problem.
We do not know if the sealed axle actually creates enough pressure to pop the seals.
There might be a lack of air space in the axle creating time that oil might leak out vents.

We don't know everything yet. I know you feel comfy with your design and I think that is great! But it is untested. A few hours is nothing.

I never said your design is not correct. For me, your design is lacking in the metal tapped into plastic. Have you not noticed my idea is very similar to yours, but I use all metal? :thumbsup: But, I do not want a pool of oil in my field or in my garage, so I am holding off on everything until others test theirs out and for the simple fact that my tractor is probably just crossing the Mexican border.

 

[Spudland_Dave]

.....for the simple fact that my tractor is probably just crossing the Mexican border.

Dont you mean "Engine" is crossing the border, heading to GA?

Is it just me or are us JD guys the only ones that can have a 5+ page "discussion" like adults? Seems most other threads in other forums (not just here on TBN) usually get locked at paged 5/6 because the posts have essentially become useless namecalling?

 

[nmu98]

Dont you mean "Engine" is crossing the border, heading to GA?

Is it just me or are us JD guys the only ones that can have a 5+ page "discussion" like adults? Seems most other threads in other forums (not just here on TBN) usually get locked at paged 5/6 because the posts have essentially become useless namecalling?

Dave,
I could be 100 percent wrong, but I think all the 3x20's and 4x20's are made in Mexico now. If not the 3x20's, my dealer did say that the 4x20 was moved there for building.

I currently have a warehouse date of the 10th for the tractor. Then it has to ship to the dealer.....

 

[arrabil]

I have a lot of currie high end axles on my jeep and they dont need a tank and they are turned in every way possible, they never leak.

There might be a lack of air space in the axle

Nmu, I believe you've got the answer to the problem right there. Its whats been bugging me since this happened. Deere specifies 7.4qts for this tiny axle. My off-roader's Ford 8.8 specifies 2.5qts. I have 3qts in mine for better cooling. Like you said, no leaks, ever, at FAR more exaggerated angles. The Ford 8.8 is twice the size axle and is supposed to hold one third the oil!!!! So the Deere axle just doesn't have enough air expansion volume. Which leads to:

We do not know if the sealed axle actually creates enough pressure to pop the seals.

I say we do know, particularly because of how little expansion room there is, and its why I went and started on the vent in the first place.

Rob, I drove my tractor forty feet, in 2wd, from its normal parking spot to a downhill location so I could empty and flush my fuel tank. On day three I noticed the oil on the ground and in the vent filter. On the fourth day I drove right back to the parking spot and the oil did not drain after another day. I hope that alleviates any confusion. I think if you look at the picture of what I made you can see it probably vents higher in the axle that do your horizontal holes. I'm not picking on your design, just saying mine isn't the problem on its own.

 

[Spudland_Dave]

Deere specifies 7.4qts for this tiny axle. My off-roader's Ford 8.8 specifies 2.5qts. I have 3qts in mine for better cooling. Like you said, no leaks, ever, at FAR more exaggerated angles. The Ford 8.8 is twice the size axle and is supposed to hold one third the oil!!!! So the Deere axle just doesn't have enough air expansion volume. Which leads to:

One difference...I'm no Petrochemical engineer...BUT....
Your Ford 8.8 has Gear oil in it...
You JD Front End Has HyGard in it (well, depending on the model)

My original question in the other thread stands unasnwered....Which seal failures are we talking about? 3x20's older Gen machines, etc...

 

[arrabil]

For me this all started because I read about an awful lot of seal failures on 42/43/4400 machines ONLY. Haven't heard about ANY issues on any other models.

EDIT: We can assume the oils expand approximately the same, and obviously the air does expand the same. So the fact that the Deere axle is filled to near capacity while the Ford axle is nearly empty by comparison, tells us something about expansion room.

 

[nmu98]

Nmu, I believe you've got the answer to the problem right there. Its whats been bugging me since this happened. Deere specifies 7.4qts for this tiny axle. My off-roader's Ford 8.8 specifies 2.5qts. I have 3qts in mine for better cooling. Like you said, no leaks, ever, at FAR more exaggerated angles. The Ford 8.8 is twice the size axle and is supposed to hold one third the oil!!!! So the Deere axle just doesn't have enough air expansion volume. Which leads to:


I say we do know, particularly because of how little expansion room there is, and its why I went and started on the vent in the first place.

Well, in your 8.8, you are only getting oil mainly to the gears, not to the sumerge the outer portions of the axle. With the tractor we are getting oil down into the knuckles and in the center pinion, so it should take a lot more oil, but....


Dave has a great point about the old axles using 80/90 and new ones using hyguard. On the axles that are failing, are they hyguard ones?

Sometimes things get pushed a bit far on the net. There is a thread in the JD forum about he MX gear boxes breaking. I have read here a long time and only read about a few. Some people might freak out reading that and look for fixes when I doubt that is really a problem.

Everyone talks about being able to open the dip stick and hearing air escape. We do not know the pressure or the volume yet. I would be more curious to put a pressure Gage on one of the axles and see what the highest reading might be. Is it 5 pounds or 50 pounds?