I have a buddy, he has an O5 TJ with a rear D44 ejecting lube.
Yes I know "friends shouldn't let friends drive wranglers", I am trying to convince him to come over to the uniframe side.
His extended LJ is a sweet build, recently, and not before in it's history, his rear D44 is ejecting lube out the vent line. The vent line goes high, exits up near the gas cap, and he hasn't had any deep water crossings this year. Did do some major (near nut vertical) climbs in Moab at Easter.
No current evidence of water in the lube. Lube level is at the fill hole level.
He does admit to using the cheapest lube he can purchase, with a justification that he changes it more often.
Would anyone have an experience with lube ejecting from the vent? Are there lubes with "anti foam" characteristics, or an additive?
He is a long term experience wheeler, running 35" and a 480's range gearing but doesn't abuse the skinny pedal. ARB locker in the 44.
Any thoughts on what would cause the lube to "pump" out. We haven't got visual confirmation on foaming yet but will be investigating futher on the next outing?
On the upside, if he can't resolve the issue I have more leverage in my argument to get him into an XJ, and I could supply him with a spare D35.
Better yet perhaps I could convince him to swap me the D44 for the spare D35, yeah, that's the ticket!

 

Suggests to me there's water in there displacing the lube.

 

Air leak in the ARB?

 

Thank you MntH.
Did some river crossings, deep enough to cover the hubs but not come in the doors.
We're going to check the fluid for water.
Thank you Salad.
Wow talk about not seeing the forest for the trees.
That is a great lead, will also follow it to the end.
Appeciated gentlemen!

 

yeah, i was talking to glen yesterday at the show and shine.
he said the fluid was just changed, so no water but was suggested by mike from TMR customs that maybe his arb was leaking. he advised the arb was off from cambridge to guelph and he was still puking fluid out. so i don't know if the compressor still sends air with the lockers off?

another slight possibility would be if there were some pitting in the ring/pinion gears, trapping fluid in the potholes then compressing it when the gears mesh, then creating it's own air pressure.

i did however turn him onto a set of diff vent bellows, and about 5 others at the show too.
even tho it doesn't fix the problem, it will keep it from leaking diff fluid on the ground.

 

Thanks Caged for the additional info on the air system being off.
Those accumulators are a good idea.
The bellows effect should feed the fluid back in when cooling down.
Hope the pressure is not too great nor accumulates between expansion cycles.
The inner lip seals should stand up to some significant pressure but at some point if the axle seals begin to pass fluid it could affect braking.