foamy gunky gear lube after 22K miles - normal?

[ilovetrains]

Just changed the gear lube after 22K miles. It was foamy, gunky and milky colored. Is that normal? Some filings on the plug.

 

[JFaughn]

If it looks milky , thats seems like moisture in there or getting in. Start documenting this , a new truck should have new parts , this could do in the r. end and probubly after the warentee , so have it opened and looked at to make sure that theres no rust issues inside , If your paying a preimeum for a new truck you should not be looking at any future issues.

 

[ilovetrains]

I was thinking about taking a look at it after another 10K, but maybe I should take it in and complain now.

 

[steved]

I was thinking about taking a look at it after another 10K, but maybe I should take it in and complain now.

How often do you drive it?? It should get hot enough to drive most moisture off... make sure the breather isn't restricted.



It does sound like water in the fluid. You haven't crossed any water that was over hub deep lately have you??



Depending on how long it was in there, it might not hurt anything or it could start making bearing noise tomorrow...



There was also a TSB out for some of the dodge trucks a while back about discolored fluid due to the gear marking compund they used during setup... might want to hunt that down and see if that applies to your truck...



steved

 

[KWentling]

Over filling will cause it to foam and look milky. Does in look like it has lots of air bubbles in it? If not it may be water in the oil. After setting it should settle out so you'll know. They want the fill level at 1/2 inch below the fill hole, not at the fill hole like a Dana.



Kim

 

[SRadke]

Foamy and milky looking is definitly water. It can foam some from overfilling depending on the oil but milky? I've never seen it.

 

[KWentling]

Easy way to tell is to let it settle out in a clear container. If it's water or other contamination it will settle into a layer. If it's air, no layer. Foamy would indicate air. Milky would indicate water or other cantamination.



Kim

 

[BHolm]

I like to just get some break in miles then change. I changed mine last week at 2500 miles. The front came out just like the stinky gear lube it is, brownish and still see through. My rear diff came out milky as well. It is normal to have some fine filings on the plug, mine did as well. Letting it settle is good advice, unfortunately mine went in the same pan with the front and the ATF from the t-case. I checked the breather and it terminates very near the drivers rear wheel well. Not sure that is the best spot considering all the filth I drive in during the winter. Never been in deep water though. While it wasn't what I expected to see, I am not sure it was water contamination. That generally turns it hot chocolate color, this was more grey/white. I'm going to put another couple thousand on and check it again.

 

[steved]

When I changed mine this weekend, the front was discolored, but I didn't think water when I saw it (it wasn't)... the rear was almost clear when I drained it... I assumed the front was more discolored because it doesn't have as much fluid as the rear (not as much dilution).



Neither were foamy, neither were milky... and both were filled to the point they would overflow out the filler hole. The specs were in TDR's last issue, it is 1/4" below the hole + or -1/4"... this is for the 9. 25 and the 11. 50, so filling it to the filler hole shouldn't make a difference.



Another thing, going back to my first post, is how often you drive... I average a lot of miles... the diff gets any moisture (condensation) "boiled off"... if you sit for a long time between drives and only do short drives, I could see water contamination from condensation. If that is your case, then might consider either driving longer trips (to get the fluid/axle hot) or more frequent changes...



This might be also the reason DC recommends the short change intervals??



steved

 

[05mxdiesel]

When I did mine at 15k, it was also foamy. I changed mine when it was warm also. Front was clear and faily clean.

 

[OT-OF-HERE!!]

Foamy, milky gear lube

Dealers have been telling me for over 10 years now that the foamy, milky appearance is normal and is caused by some additive they use in the fluid. I thought this sounds like cr. . p! I changed it and checked it a few thousand and the same thing. If you check it out I think you'll find it is normal.

 

[JTodd]

If you havent been though any deep water its unlikely there was enough moisture involved to discolor the entire volume of the diff to a milky color. If you have the Limited-Spin option in the rear-end, it is likely there is a friction modifier added to aid the limited-slip mechanism that can cause foaming and milky discoloration...



JT

 

[steved]

If you havent been though any deep water its unlikely there was enough moisture involved to discolor the entire volume of the diff to a milky color. If you have the Limited-Spin option in the rear-end, it is likely there is a friction modifier added to aid the limited-slip mechanism that can cause foaming and milky discoloration...



JT

Umm, no LS friction modifier in the AAM axles... that is a no-no.



steved

 

[DavidBurt]

Changed mine at 15k fluid looked fine not dirty or milky but there was alot of metal on the drain plug. So I took it to the dealer and let them change it they said everything is ok normal wear in. Second on the friction modifier the AAM axles do not require any modifier.

Dave

 

[ilovetrains]

If you havent been though any deep water its unlikely there was enough moisture involved to discolor the entire volume of the diff to a milky color. If you have the Limited-Spin option in the rear-end, it is likely there is a friction modifier added to aid the limited-slip mechanism that can cause foaming and milky discoloration...



JT

No deep water, but do have the anti-spin. Or course I did not add anything other than Valvoline gear lube, so now is it messed up?

 

[ilovetrains]

forgot to mention, the front looked fine and did not change it.

 

[juicedcummins]

Did mine today the rear was foamed up real bad and milky. The front was grey and no foam.

If this thing was overfilled it came that way from the factory. Now it is filled to the bottom of the hole.

 

[CumminsWill82]

I had the same issue with the rearend lube foamimg not milky but alot of foam and i was running valvoline syn 75w140 and drained and refilled with Mobil1 syn 75w90 and no foaming at all. If you pull heavy with the Mobil 75w140.