FYI: Axle seal leak cause.....INFO from mechanic "Good or bad?"

[jhous]

Just got my tractor back today after having both front axle seals replaced. I talked to the mechanic that did the job and he said the number one cause of seals leaking is breather caps stopping up (On my J2020 it''s the cap on the right side of the axle). He said when the hydraulic fluid warms up it expands (of course) and if the 'breather cap' is plugged up it will cause the seal to leak. I am assuming he means also that the hydraulic fluid in the axle is full.

I don't know. I know I stir up a lot of dust when I use my tractor and it has every reason to get stopped up. If he's right, then I guess checking that regularly should be routine.

What do you guys think?

 

[whis]

I don't buy that on a slow moving tractor

 

[jhous]

I don't buy that on a slow moving tractor

I don't disagree with you but would it not be more a function of the heat (ie. expansion) of the fluid than the speed of the tractor. I know both my backhoe and FEL definitely warm the hydraulic fluid up when I use them a lot. The backhoe really does it because I'm running at max engine rpm (which means max hydraulic pump speed also) while sitting still for extended periods. That makes the fluid very hot and it's got to expand pushing the air out somewhere and if the breather is stopped up that leaves the seals as the next weakest spot. But, that's just speculation on my part.
In any case, thanks for your input. Your thoughts hold as much validity as the tractor mechanic as far as I'm concerned. I've met too many of them that tried to BS their way through a question in stead of admitting they didn't know.

 

[Coyote machine]

Overheating fluid in the axle housing, with no way to depressurise the air displaced by the expansion of the fluid could blow a seal. If the breather does not allow equalization then something has to give. Axles are only filled to a point where the air pressure can escape via a breather. Usually the fill plug allows for enough fluid to keep the bearings and gears covered in gear oil /hydraulic fluid.

It is possible the axle might have been overfilled or the wrong type of fluid was used.

 

[bruceatlam]

I don't buy that on a slow moving tractor

I don't either. The front axle isn't part of your hydraulic system. At least not on my tractor. And I can't see any way that your front axle components move at any speed that would heat up the 80/90W oil that's supposed to be in the front axle.

 

[whis]

I don't either. The front axle isn't part of your hydraulic system. At least not on my tractor. And I can't see any way that your front axle components move at any speed that would heat up the 80/90W oil that's supposed to be in the front axle.

exactly

 

[Coyote machine]

exactly

This means nothing, the whole 'it's not part of the hydraulic system'. It doesn't matter. Heat is generated by movement of the gears and bearings in the axle. Fluids expand from friction and cause a need to vent gases generated by same. Thus without adequate venting something needs to give. In this case it is the seals. End of story.

 

[sd455dan]

Just got my tractor back today after having both front axle seals replaced. I talked to the mechanic that did the job and he said the number one cause of seals leaking is breather caps stopping up (On my J2020 it''s the cap on the right side of the axle). He said when the hydraulic fluid warms up it expands (of course) and if the 'breather cap' is plugged up it will cause the seal to leak. I am assuming he means also that the hydraulic fluid in the axle is full.

I don't know. I know I stir up a lot of dust when I use my tractor and it has every reason to get stopped up. If he's right, then I guess checking that regularly should be routine.

What do you guys think?

He said that the breather was most likely the cause and yet did not mention whether he checked it replaced it or possibly cleaned it.

So If his theory is right- the problem may repeat the next time you work the tractor/ front axle hard?? I would want to Know if the breather was even checked, also condition of the support bearings and If there was play in the drive assemblies.

 

[azranger]

I am taking mine back for the second time for this very issue, first time was about 100hrs. At that time the mechanic did not know what caused it, no play in the axle or bearings, but went ahead and replaced the bearings as well as new seals. Now 140hrs its going back. when I called the dealer to let them know of the problem again, he called the manufacturer, and they told him they have an "updated/newer" seal, which leads me to believe LS knows that there is a problem with the old seals.As far as the vent being plugged up causing it???Maybe, but I'm not convinced. I hope it is that simple, when I get mine back I will look closer into it.

 

[Ford850]

How many other tractors have a vented axle? Have any of you with failed seals checked the vented plug to see if it is actually clogged? Just curious. I know my CIH is not vented.

 

[pmsmechanic]

How many other tractors have a vented axle? Have any of you with failed seals checked the vented plug to see if it is actually clogged? Just curious. I know my CIH is not vented.

My John Deere 4410 front axle is not vented either. If you check the oil when it's warm the oil fill cap releases quite a bit of air pressure. So far I haven't had any issues with oil leaks.

 

[jhous]

He said that the breather was most likely the cause and yet did not mention whether he checked it replaced it or possibly cleaned it.

So If his theory is right- the problem may repeat the next time you work the tractor/ front axle hard?? I would want to Know if the breather was even checked, also condition of the support bearings and If there was play in the drive assemblies.

........................................
My bad. The mechanic told me he took the breather off and cleaned it.

 

[jhous]

How many other tractors have a vented axle? Have any of you with failed seals checked the vented plug to see if it is actually clogged? Just curious. I know my CIH is not vented.

.........................
My opinion is that whether or not the front axle is vented depends on the overall design. This LS axle is made to the filled will gear oil with very little room for air (the dip stick to check it is a very short little sucker so the oil has to be just about to the top of the horizontal part of the axle thus not allowing for much expansion room before something has to vent. A different design may only have oil in the bottom and depend on the gears to slosh the oil around. Just sayin'. My take away is to watch for another leak and barring one, clean the breather on a regular basis.

 

[sd455dan]

........................................
My bad. The mechanic told me he took the breather off and cleaned it.

- that sounds like good news .
Also after reading post 13 the fact that there is very little expansion room in the front axle would likely make a vent pretty important...
my 4x4 tractor is the type that is filled 1/2 full ( if that) and it still has a breather to.
It seems the majority of 4x4 tractors are equipped with a vent, but I was not aware that some designs were filled to almost the top, that is interesting :stirthepot:

 

[SPYDERLK]

Overheating fluid in the axle housing, with no way to depressurise the air displaced by the expansion of the fluid could blow a seal. If the breather does not allow equalization then something has to give. Axles are only filled to a point where the air pressure can escape via a breather. Usually the fill plug allows for enough fluid to keep the bearings and gears covered in gear oil /hydraulic fluid.

It is possible the axle might have been overfilled or the wrong type of fluid was used.

Expansion of the air above the oil is way major in comparison. But that volume is compressible, and if not overfilled badly, there is plenty of room so pressure will stay low. We are talking only a couple psi at normal op temp. At ~oil boil T it would get up to 15psi, but youd notice the paint changing color.