Just when I thought that every possible leak had sprung! My coolant leaks, my power sterring appears to be leaking, my pan gasket leaks, my rear main seal leaks, and now my friggin rear axle is leaking... sort of.

Any idea why the vent tube on the rear axle would be burping tranny oil? The vent tube comes from the right (driver's side) side of the axle at the brake line T.

 

The vent tube on the rear axle is burping tranny oil??????

 

Do you drive through a lot of deep/ish water?

 

I geuss I should proof read my posts before I post them. No it's burping gear oil.

Furball, I drive back and forth to work mostly. It never gets offroad action... sadly. It just started within the last few days. The only change is the outside temperature but it has only gotten colder in the past few days. The vent tube comes from the drver's side (left) axle tube and goes to the frame rail where it is attached by a clip. It has leaked bad enough that it soaked the frame rail, dripped on to the axle and made a pretty good mess on the driveway.
I assume that it had a pressure build up in the axle for some reason but I have no idea why.

 

This is a timely post. The very exact (well, mostly) same thing has happened to me. The passenger side rear axle leaked at the seal when I bought my truck last May. The drum was coated in diff oil. I replaced the seal and bearing (finally) around August. Cleaned up the brake drum and pads using rubbing alcohol (not a permanent fix, but I wanted to be sure the problem was solved before I replaced any brake parts!). Also drilled out the axle vent and put a new tube on it (since the old one had been torn off).

Everything seemed to be okay. Until the temperature around here started getting colder. Around mid-October. I'd take the truck for a spin (it's not a daily driver) then park it. I'd check to see if any oil was leaking out the drum (mine don't seem to have those rubber plugs that cover the star wheel) and nothing would be there. A day would pass and oil would be leaking out. Hrmmm.

Drove it again several days later and parked it and nothing. No leaking. Several days passed and I would check under the truck every morning. Then suddenly: a Leak! What the heck? The truck has just been sitting there!

Cleaned up the wheel and the rim and took the truck out for a spin (to pick up a christmas tree nonetheless!). When I got home I checked under the truck and either I didn't do a great job cleaning up or the axle had leaked while the truck was parked at the Christmas tree place. But nothing was leaking yet vertically straight down from the latest trip (if that makes sense). A day passes and there's way more oil than every before leaking down from the brake adjustment hole and down onto the rim and down onto the tire inner sidewall and onto the driveway. This is puzzling and very annoying.

Anyone got some ideas as to what the problem might be? The bearing and seal was one of those new one-piece tapered roller bearings. So I didn't have the opportunity to ruin the rubber seal with the splines from the axle. Could it be that the axle housing is the problem in my case? Or does this sound like there's a vent problem?

And why does the cold temperature affect this? Doesn't oil get thicker in the cold??? Makes more sense that there would be a leak when its warm.

Also, I don't go offroading and don't take the truck out in the rain. Of course, I have no idea what the PO would have done with it. Could there be water trapped in the axle that is causing a venting problem? Or did I manage to overfill the oil...even though I just filled it til it started coming back out.

Finally, could this have anything to do with the tightness of the bearing retainer plate nuts? I took them to the minimum torque spec (I think its like 45 lb/ft).

 

Yesterday I took the opportunity provided by really warm weather and took the brake drum off of the rear axle that's been leaking. The weird thing is that the drum itself isn't getting saturated with oil, which is the way things were before I replaced the bearing and seal several months ago. Instead, the oil just dribbles/runs out of the dimple/channel (whatever its called) in the bearing retainer plate.

Aside: I've always wondered what the correct orientation for the bearing retainer plate is supposed to be. One side has this dimple/channel/trough in it. When I disassembled the channel was at the bottom. But the exploded diagram's of the bearing/seal in both the shop manual and the Haynes book show this channel at the top. The other (non-leaking) side has the channel at the bottom too. What the heck is it for?

So here's the weird thing. I decided to remove the nuts and slip the retainer plate forward so I could see where the oil was coming from exactly (that is, from the outside of the race or from the inside...if the rubber seal was broken). Well, I didn't expect to be able to move the plate out very far because when I originally removed the axle several months ago I had to attach the drum in reverse to make a quasi-puller--cuz the axle was being held in somehow. But this time the axle just popped right out. I pulled it out just far enough and could see the rubber seal was in one piece but...

Well, the bearing and seal were fitted together as one piece when I reinstalled the axle (again, several months ago). So how would the rubber seal ever slip around the race properly now if I slipped everything back in???

Anyhow, I reassembled the whole thing and added silicone behind the retainer plate, even filling the channel mentioned above. I don't expect this to fix anything but thought what the heck, may as well do something. The torque specs for the retainer plate are 50-75lbs so I took it to 65 this time. If I pull on the axle hub now, it moves out only slightly whereas before this it felt a bit looser.

As you can guess I'm pretty puzzled about this whole situation. Just don't have enough experience with the components. Any guidance would be appreciated. Oh, and of course I'm wondering is this bearing/seal now ruined? And why was I able to pull the axle out so easily?

 

Bump. Anyone???

 

Hey Toolz,

You didn't mention what truck you were working on? You shouldn't have been able to pull the axle without draining the differential, dropping the plate, and removing the pin and c-clip that locks the axles in place.

 

Gib is right on that, you have to open your pumpkin in order to get an axle out, unless there is some major issues. Sounds like you really need to get in there and check things out.
GotLift, have you ever done any service on the rear end? When was the fluid last changed? Does it act up at speed (ie: jerking/clunking/squeeling)?