what is this leaking on my rear axle? pic inside

fiveoho

15 Year Member
Apr 28, 2005
1,958
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69
TN
i took the wheels off today to paint my calipers and i noticed what looks to be a grease fitting on the passenger side of the rear axle housing leaking. it appeared to have leaked at one time or another but im sure if it currently is. the grease ,or whatever it was, was wet. i tried to tighten the cap that covered it but it wouldnt tighten. it also wouldnt come off either.

what is it?

View attachment 310011
 
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I think your seal is leak, AND DO NOT USE YOUR REAR DIFFERENTIAL AS A JACK POINT. !!!!!!!!!!!!!!!!!!!!!!!:mad: THAT WILL MAKE IT LEAK EVEN MORE !!
 
I beleive it is a breather for the rear axle.

I may be wrong, someone correct me if I am.

There also may be a plastic hose that should be routed up and out of the way missing, causing your leak.
 
I think your seal is leak, AND DO NOT USE YOUR REAR DIFFERENTIAL AS A JACK POINT. !!!!!!!!!!!!!!!!!!!!!!!:mad: THAT WILL MAKE IT LEAK EVEN MORE !!

ive lost count of watching reputible mechanic use the diff as a jack point. i always just assumed that was ok. where is a better place to use? thanks for the advice man
 
where does the hose go or attach to?

If there were a hose, it would be routed up or out, in case you are ever up to your axle in water, lol.

Its not a grease fitting, as everything inside the rear end assembly is lubricated by the differential fluid.

Correct mine doesn't have a hose though.

Come to think of it, mine may not either.

But I do think we are right on it being a vent.



Most, if not all (older anyway) 4x4 trucks and SUV's have a hose routed up HIGH so water/mud stays out of that opening.



As far as using the pumpkin for a jacking point, its fine. I wouldn't reccomend leaving it jacked up like that for an extended period of time (more than a few hours, personally). At that point i'd slip some jack stands under there and let the axle rest on them. Most of the time thats what I do anyway.
 
That's definitely the breather tube barb. You can buy a piece of hose to slip over it, and run it upward anywhere you can. I have about a foot long piece of rubber hose on mine that just aims straight up. Mine leaked there when the hose fell off once, so I threw a little hose clamp on it. One thing I noticed is you still have your mott bar installed. Remove that useless hunk of metal for a little weight savings!
 
My mott bar decided to detach itself going down the highway. At least 1 bolt anyway.

It was swinging around banging into my axle, scraping on the road. I took that SOB off ASAP!!!
 
That's definitely the breather tube barb. You can buy a piece of hose to slip over it, and run it upward anywhere you can. I have about a foot long piece of rubber hose on mine that just aims straight up. Mine leaked there when the hose fell off once, so I threw a little hose clamp on it. One thing I noticed is you still have your mott bar installed. Remove that useless hunk of metal for a little weight savings!

is the mott bar the thing on the bottom of the diff, with 2 bolts? i still have mine on, but never knew what it was for, or what its supposed to do?
 
is the mott bar the thing on the bottom of the diff, with 2 bolts? i still have mine on, but never knew what it was for, or what its supposed to do?

Yes.

It is there to absorb drivetrain vibrations.

Its only 8-10lbs, so its no biggy to remove it.

Supposidly its effects are negated once you switch out the stock gears... so the e-mechanics say.
 
its called a dog bone.. leave it, it does no harm.. and as for jacking on the pumkin, i do it all the time, ive seen people do it all the time with 0 problems.. its more of a spec thing then anything.. the rear axle actually has camber to it so its bent a little.. if you jack it from the pumpkin its supposed to lessen the camber, psshhh.. i dont beleive that it would hurt it. but dont take my word for it..

the spot that you have oil leaking from should have a little plastic hat on it to prevent oil from spilling out, its not there anymore.. you could put a hose on it i guess, it would work.. but yes its just a vent, nothings wrong with your axle besides the hat
 
its called a dog bone.. leave it, it does no harm.. and as for jacking on the pumkin, i do it all the time, ive seen people do it all the time with 0 problems.. its more of a spec thing then anything.. the rear axle actually has camber to it so its bent a little.. if you jack it from the pumpkin its supposed to lessen the camber, psshhh.. i dont beleive that it would hurt it. but dont take my word for it..

the spot that you have oil leaking from should have a little plastic hat on it to prevent oil from spilling out, its not there anymore.. you could put a hose on it i guess, it would work.. but yes its just a vent, nothings wrong with your axle besides the hat

actually theres still a plastic cover on it, its just loose. i cant tighten it or take it off either. is gear lube whats coming out? should i get this fixed asap?

well, im not sure if i was right or wrong using the pumpkin as a jack point. i see theres several different opinion on that. i did make sure not to bend the diff cover in any way. i had jackstands under it for safety but the weight rested on the jack for less than 2 hours, long enough for me to paint the calipers. i just dont wanna hurt anything under the car by doing it that way :shrug:
 
The reason they say not to jack on the pumpkin is to not damage the cover, which overlaps the housing (being slightly larger than the housing itself), and to not damage the front ears where the weight damper thingy hangs. If you jack on the housing itself it shouldn't be too big a deal, but could stress out the pinion section and lead to a crack eventually, but i wouldn't worry about it too much.

That is a axle vent/breather. Somebody overfilled your rear axle and/or it is over heated and blowing off excess fluid that is boiling over. It's not a big deal, check the fluid level and do a drain/exchange just to be sure with the PROPER amount of fluid.