So go back to when it started and what might of happened to cause it. Any work done to the back end? Any chance of water submersion or temp changes, is the axle showing any sign of heating up during operation?

 

as far as i can remember its happened ever since i started the engine the very first time. i had not clue where it was coming from until i accidently moved the breather hose for the front axle.

 

The breather hoses (front & back) are there to relieve the pressure caused by the angular momentum of the diff internals whipping around the 90 grade. (I'm sure we all know this....just thinking out loud here). But, there's no way there would be any pressure build up in the differential(s) at idle, when the vehicle is stationary. Inside/outside pressure are at equilibrium...

Something sure is a-miss here....that hose should be the only thing coming off your axle....except for the brake lines.

There's no way the hose and nipple are clogged? I took mine (breather nipple) out and drilled it for a little larger diameter and better breathing.

 

Had oil leak out of my breather when the left axle shaft got stuck in the locked position. Only leaked out the breather when driving down the freeway, though.

 

well i dont have a clue what to do with this one. the hubs turn free in and out so i dont think anything is stuck. i had the truck running for less than 5 minutes and it started to leak. this issue and tranny issue are driving me nuts. I even called the local axle shop and he told me i was crazy. It can happen.

 

Can you maybe post a pic or a video of your problem. That may help us help you better diagnose the problem. At this point I'm thinking it may not be your axle. The only time it should build any kind of pressure is when in 4x4 and rolling down the road or on a trail. Simply starting and running the engine with the truck stationary simply shouldn't do anything. They only way that could possibly do that is if you some how have a vacuum or pressure line hooked from the engine to the axle.

 

i will try to post a video but not sure if i can. I know this sounds really out there but there is nothin hooked to the axle but the breather hose and the brake lines. I have no clue what is causing the front axle to build pressure. it might be a few days, have to pull the tranny out and have it fixed. dont know what happened to that.

 

i still have issues with this. I tried to post a video but i am not computer savey. anyone else have any ideas why this would happen. its driving me nuts.

 

1)Is there anything on the end of the breather hose? sounds crazy, but I had a 1-way valve on one of my trucks, which was supposed to prevent anything entering the line(water), but allow for pressure to escape. What it did was act as a syphon, and suck fluid out. I solved the issue by removing the piece on the end, so It was just a bare hose.
2) imilarly, if there was a section of tube inside the axle attached to the breather, or if oil managed to get into the breather tube the mere trembling of the vehicle under power would create a syphon scenario.
3) The only other thing I can think of is the type and weight of the oil. check this link out.ZJ D35 Axle Vent Tube Syphoning Off Differential Fluid.

Pop the plug on your diff, right after you get done with a drive. Check to see if your oil is foaming. Then, while the plug is off, blow air through the breather to try to drain the line.

Other than cleaning the line, or changing to a different kind of oil, there's nothing else I can think of. very strange

 

The hose was open on the end, no one way check valve or anything. I will chekc the diff when i get home and see if its foaming or not. Thanks for the info. its something new to try and i will give it a whirl

 

The OP has never really answered the question as to whether the oil is getting hot. Can you hold your bare hand on the housing when this is happening?

 

never tried to do that. i will when i get home in a few hours and let you know if the housing is hot or not.

 

I wonder what will happen when you get to drive it? Maybe that will cure whatever ails the differential. It certainly is strange.
Good luck And -great looking build. Have fun on your trip back to AK

 

so come to find out that the diff was messed with some time back a few years. turns out a rear diff cover from a car will fit the d44. so the fill hole was way to high and that was why 90wt was blowing all over the truck. sorry to get everyone in a bunch over something that was done years ago and i didnt know about.. Thanks for all your help.

 

Glad ya got it fixed. Gotta love simple fixes!