Water in rear axle? HELP!

[JLS]

This weekend I was going on a trip to Birdseye near Leadville, CO. Before I went I was checking all my fluids, first time since I bought it, and noticed that the rear diff oil was milky. From what I remember this means that water is getting in and contaminating the oil, correct? When checking it I noticed that the check plug was not tight at all. So I suspected this was how the water got in. Not so. If you have seen my post from EE's bulletin, I was curious if I could put GL5 gear oil in the diffs. I didn't get a difinitive answer before I left so I went ahead and put it in. Today on my way back I stopped at a Car Quest and got GL4 and proceeded to change the front and rear diffs and on the rear it was contaminated again! So where do I start to diagnose the problem? Also if it is a rear axle seal how do I determine that and how hard is it to change them? I don't see any leaking on the rear diff or axle except for the first time I checked you could see how oil was coming out the check plug. If you don't know birdseye there is a couple of creek crossing so this is how it got contaminated again. Anyways, any help would be greatly appreciated.

TIA,
Jeremy Sebestyen

 

[Lutzgaterr]

My first target would be the axle vent tubes. They are the common culprit to many water contaminations. If you have not extended these into the engine bay, do it. Make sure the valve from the axle tube is sealed. While you are at it, extend the Transfer and ****** tubes as well.
Second, could be axle seals, so pop-off the hubs, clean and repack the bearings and get 4 new seals for both axles.
BTW, be careful with tubing and heat issues within the engine bay. Last thing you want is axle vent tube melting and shutting down any pressure release, then you get begin to see other leaks appear.

 

[JLS]

Thanks! I will start with the axle breather tube and niple. One other thing, can you tell if your wheel bearings need to be repacked because everything "Seems" to be fine. I just bought this rig not too long ago. It is a 99 D1 with 51k miles on it. Is that a normal time to have to replace the wheel bearings?

 

[Blue]

The fact that your gear oil was milky the second time could just be residual contamination - change it again after a few hundred miles and see if it's cleaned up at all. To prevent further contamination, do what's been suggested. The first and obvious thing to do is to make sure that the fill & drain plugs are tight! As far as repacking your bearings goes, you should do this if you're replacing your hub seals - repacking is not the goal, replacing the hub seal is....but as long as you're in there you might as well do it. In my opinion, your hub seals may be fine and tearing into it could be a waste of time & money. Start by tightening your diff plugs, then see if your gear oil cleans up after a few changes. If you play in water a lot, then you should inspect & extend your breather tubes, too.