Water in Diff causing vibration like bad u-joint?

[little x]

Now that I know that there was water in the diff I thought I'd rename the thread, and edit the 1st post with a new question related to the original (instead of making a new thread).

So, the reason I decided to pull off the rear diff was because I already had the truck up high on some tall jack stands (to give me more head room while replacing drive shaft u-joints). I pulled off the drive shaft, only to find that both u-joints are just fine, no binding, completely free. So, could water in the diff have caused the truck to vibrate as if the u-joints were bad. It was a vibration that got worse with speed, I was positive it was the u-joints, it felt like it was coming from the rear end. If it did, could I have done any damage to the ring and pinion. I checked them out, but I don't really know what I'm looking for, other then metal shavings.




(original post VV )
I pulled off my rear diff cover today to replace it with a metal one and add a diff guard. I was some what alarmed when the fluid coming out was very foamy / frothy. I didn't remember gear oil being like that the last time (maybe 2 years ago) that I changed my gear oil. Is this anything to be concerned about?

 

[Verno]

if it is milky as well as frothy then you have allowed water to get into system somewhere. Double check that your diff vent (if equipped) isn't allowing water to enter.

 

[manaen]

yup you got water in there. did you drive through anything deep lately?

 

[bisjoe]

Yes, drain it and replace all of it. The vent is usually a rubber hose and it can get water if you drive through a flooded road despite the one-way valve that's supposed to be on the end.

If you go offroad through streams, best replace it with a longer hose and run it up into the fender well.

 

[little x]

Yes, I do drive through deep water.
The factory breather hose is replaced with a hose that runs into the cab, up the D-pillar, and tucks under the headliner. That worked great for a few years, but I'm guessing that after removing the rear windows last summer that is no longer a dry spot. I'll relocate the end of the hose elsewhere.
Thanks, that's what I thought the problem was, but I wasn't sure.

 

[little x]

Bump
I'm waiting for RTB to dry before I can add fluid and take it for a test drive. Just hoping some of the experts would chime in and let me know if this may solve my problem, or if I'm going to have to look elsewhere for my vibration issue.

 

[Verno]

How did your ring & pinion gears look? was there much metal shavings? I'd say as long as the gears look good (no hot spots or broken/worn teeth) then you probably caught it before serious damage.

 

[little x]

The gears looked perfect as far as I could tell (no discoloration and no obviously worn sections) and there weren't any shavings.

Could watered down gear oil have caused the gears to bind, let go, bind, let go rapidly like a bad driveshaft u-joint?