Gear oil spewing from vent line on newly swapped XJ44

So like my other post about the ujoint says I swapped out my 8.25 for a newly geared and ARB'd XJ44 2 nights ago and last night i stopped to get gas and found a lot of gear oil spewing from the vent line, it was not tied up high must have come loose so i dont know if that is the main reason. I got it pinched off so its fine for the time being but should there even be fluid where the vent comes off the axle tube. I thought that there should only be fluid in the center section and I right? Also is capping off the line a good or bad idea or should i just secure it better and call it good. Thankx in advance.

Every D44 Ive ever torn into ,on rears only mind you, has only outer seals at the brake backing plates, lube will flow to the outer ends to get the axle bearings. So yes to your question. The front 44s are different in that there is a inner seal that is accessed by removing the gears after removing the bearing caps.This is why there is only a slinger type seal on the axle tube and the front wheel bearings are sealed units or have their own grease seal. Make sure your diff isnt over filled or running overly hot from incorrect assembly. After a good drive it should be fairly warm/hot to the hand and not blazing hot.

Awesome thankx. I think the reason is just because the vent line came loose and was basically parrallel to the tube allowing fluid to escape. My thought was that the axle bearings in the rear are on the outside of the seal so there would be no need for the oil to be in the tube. Im goin for a 30 min. drive here in a bit so I will check how hot the dif cover is. There is no oil coming out at the backing plate so those seals are good. When i originally filled it I just poured till a little bit ran out the hole. thankx alot.

Do not leave it with the vent line pinched off. They put the vent there to vent -- if you pinch it off you will increase the likelihood of forcing gear oil past the seals.

OK so I really need help guys. I just drove for about 30 min. or so and when I got out the damn thing is still spewing oil out the vent line. Before I left I unpinched the line and secured it about 6 inches or so above the axle tube and its still doing the same damn thing. This cant keep happenin I have way too much invested into this axle to allow this to continue, I cannot think of what could possibly be creating so much pressure in there for this to happen. Even after this had lost about 1 of the 2 original quarts of fluid last night it was still creating enough pressure to cause fluid to spew out of it. PLEEEEASE HELP!!!!!

Take a look at this article. http://go.jeep-xj.info/HowtoAxleBreather.htm

The D44 does have inner tube seals i believe, they are just on the outside of the carrier bearings

Most everytime I do any diff work, I keep an eye on the the temps., figured out a long time ago, around 160 F is about the max temp. where I can hold my fingure on there for a few seconds, without serious discomfort (welders fingure), the temp. for the fingure test may be a bit lower for other people. Or in other words, when it´s too hot to touch it too hot. Long high speed runs up the interstate, will heat it up often, a little too hot to touch (better to test after moderate speed runs). I check in two spots, the diff cover (low) and near the pinion on the case.
I´ve had some trouble with the vents, regurgitating fluid, it was usually excessive RPM´s. Vent tube should be as high as practical, without traps (low spots), it should always be going uphill. A low spot will eventually fill with oil and will often spurt out the top, when pressure builds.
Have found the quality of the gear oil, plays a roll (cheap oil foams easier). Really only a few reasons for the oil to come out of the vent.
Thin oil, oil too hot (thin oil), cheap oil that foams, too much oil. I run 140 wt. do a lot of 80+ MPH driving and occasional towing.
I often do comparison tests. Take one XJ, for a drive (measured distance) take a few spot temp. readings (electronic thermometer) on the diff. case, tranny, motor whatever and compare them to another XJ with problems. Diff may have a significantly higher temp. when something is too tight.
Might be worth a look in the diff. case, high temps often discolor the ring gear a bit, metal turns dark or anywhere from light blue patches to black patches, same with the bearings.

8Mud said:

Most everytime I do any diff work, I keep an eye on the the temps., figured out a long time ago, around 160 F is about the max temp. where I can hold my fingure on there for a few seconds, without serious discomfort (welders fingure), the temp. for the fingure test may be a bit lower for other people. Or in other words, when it´s too hot to touch it too hot. Long high speed runs up the interstate, will heat it up often, a little too hot to touch (better to test after moderate speed runs). I check in two spots, the diff cover (low) and near the pinion on the case.
I´ve had some trouble with the vents, regurgitating fluid, it was usually excessive RPM´s. Vent tube should be as high as practical, without traps (low spots), it should always be going uphill. A low spot will eventually fill with oil and will often spurt out the top, when pressure builds.
Have found the quality of the gear oil, plays a roll (cheap oil foams easier). Really only a few reasons for the oil to come out of the vent.
Thin oil, oil too hot (thin oil), cheap oil that foams, too much oil. I run 140 wt. do a lot of 80+ MPH driving and occasional towing.
I often do comparison tests. Take one XJ, for a drive (measured distance) take a few spot temp. readings (electronic thermometer) on the diff. case, tranny, motor whatever and compare them to another XJ with problems. Diff may have a significantly higher temp. when something is too tight.
Might be worth a look in the diff. case, high temps often discolor the ring gear a bit, metal turns dark or anywhere from light blue patches to black patches, same with the bearings.

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Well I replaced the vent line and have it running over a foot straight up and into a catch can so I can watch how much fluid its loosing in the thought that it might have been restricted somewhere causing the gases to flow at a higher rate and possibly pulling oil along with it. This did nothing. As far as RPM's my speedo is not correct with the 4.88's and 35's but at highway speed Im only spinning 2250 to 2500 so i dont think that is the issue. I have been running valvoline 80-90 and filling it just till it flows out of the plug. Im completely out of ideas as is everyone that I have spoken to outside of this forum. Unless someone has ideas Im just goin to have to wait till I can my XJ back to the axle shop. If anyone has anymore ideas i would like to hear them. Thankx for about the fifth time.

Not a Jeep, but the front on my Chev, would throw a geyser of oil out the vent on occasion. The top of the vent was a near 2 feet above the diff. Race oil helped. The solution was an expansion can near the top, Made a can with about half a pint of volume, with a 1/4" in and out nipple. Oil that made it to the top of the vent would expand and coat the inside of the can, cool and drop back into the diff. Never did have anymore trouble. Could probably do the same thing with a short piece of 3/4" inch copper pipe and a couple of reducers on the ends, mounted someplace on the vertical.
Blow in your vent line, should be very little restriction. Have often seen vents plugged or partially plugged.
Is it possible you left some solvent in the tubes, then added oil? Not really that much oil in a diff., a pint of solvent could thin it significantly.
Most every time I´ve had one vent fluid, it was because the oil foamed/thinned or a vent was plugged or partially plugged.
I´ve got a couple of mil spec. vents with a piece of foam in the inside end. Always wondered what it was for. to help keep the oil in or the water out, maybe to strain solids out of an water that found it´s way in? Maybe all of the above.
Most 44´s I´ve had, that never vented oil, had the vent as close to the pumpkin as practical (have seen the vents in different spots on various 44´s). Dodge liked to install the vents on the diff. housing just to the outside of the carrier bearings, the wide spot (cast part) of the axle tube.
With the vent tube end from 18-24" high, I´ve rarley had any serious venting.
Last thought, have had water in the diffs. make steam/foam and blow crap everywhere.

i don't have my manual in front of me for the arb d44. but i seem to remember that there was a mention of having to make sure that there was a return/drain slot on the "vent side" of the axel at the bearing interface. it looked like in the installation manual they cut a small slot. my 44 currently pumps oil into the non-vent side and builds up enough pressure to leak out the passenger outer seal onto the brake backing plate. when i looked down the tube when installing disc kit there was a small hole in the shim plate (or a solid looking plate anyway) that maybe should have been indexed to the bottom and so i do not get it to drain back. anyway , check the manual. when i get back home this weekend i will dig out mine to see if i remembered correctly. good luck!

Thats an idea ill look into that. thankx.

I am just getting to this but I think you nailed it on the head. talk to the diff shop. they forgot to drill a hole behind the driver side bearing cap. its to allow fluid to drain back into the the diff from the axle tube.

If that is the case is it safe to drive. This is my DD and I need to drive it back and forth to work, its only a couple of miles.

Thankx for the help everyone. I got it back to the shop and that was def. the problem.

Rawbrown said:

I am just getting to this but I think you nailed it on the head. talk to the diff shop. they forgot to drill a hole behind the driver side bearing cap. its to allow fluid to drain back into the the diff from the axle tube.

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i'm having the same problem w/ my D44 and wonder if this (above) is the source? should i be able to see this hole if i pull the diff cover? i'm gonna change the fluid in the morning anyway...

thanks in advance.