Minnesotamike

When I bought my new truck I watched (and they did let me in the shop) the techs change my differential cover over and the oil looked white in color. Now I know from previous threads that guys say it say its because of gears meshing and breaking in but when I did my 5.9 it looked ok compared to this truck, I also had 3.73 in my 05 and now have 4.10 (probably doesn't matter) anyways it makes me want to do the front diff with synthetic also but a lot sooner then the manual says.
Something to think about.

coolbreeze

Don't the new trucks come with synthetic in the diffs?

ciamcoop

What do you mean it looked like milk? Light brown color? Sounds like it has water in it. Maybe the vent is leaking, or it was stored in a lake before delivery.

GasganoFJ60

The only thing I can think of is you somehow got water in the axel.
Been playing in the med or driving down some flooded streets?

Ive also heard that the synthetic that comes in most axels now a days is a quick break-in oil. Ive heard that you must change out that break-in oil before the first oil change in some cases.
Thats just what a few little birds have told me.

KMKDiesel

yep your on the right track if its turning milky light brown or white then you diffently have water in there.

caper11

I think the only thing in these trucks that is not synthetic is the engine oil, do you own a boat? could of got water in it at the launch.

DiEseLjunKy

Did them little birdies have towels wrapped around their heads and pray to Mecca 3 times a day?

MtnTrucker

It could be water, though that isn't impossible it doesn't seem likely on a brand new truck. If you drove it a few miles before you went to the shop, and they put it right on the lift and dropped the cover, you could of just been seeing air suspended in the lubricant. If you would've waited an hour or so I bet it wouldn't have looked the same.

CamperAndy

What did the techs say? If they said nothing then it was most likely nothing out of the ordinary.

I agree it could have been air.

Minnesotamike

I should of said it looked nasty (not as runny as milk), this was something that I read about a while back when some other guys were talking about it last summer; didn't really believe new oil could get that bad that fast, the truck was not driven in the rain and it was sealed up tight.
It was most likely the gears breaking in and got the color from fine metal shavings.
But I am changing the front as soon as I get a front dif cover (holds more quarts), more oil the better. Unless it’s in your hair.

Need95-00CTD

Without a picture I can't tell you for sure, but I've done plenty of testing with axles, as I was a test engineer/technician for Dana for a few years. No matter what, you should not have metal shavings, no matter how fine, in your diff fluid. Bearings shouldn't shed much if any metal, same with the gears.

If its milky, its got water in it... I've pulled diff's that had been run for weeks after letting them cool 15-20 minutes, and while hot aired up oil looks slightly lighter, I would not say it looked milky, more like a coffee with a touch of creamer.

Check your breather tubes, while you may not have driven the truck in rain or water, the truck, or more likely, the axles may have been subjected to water before you got it.

We had a problem with a few of our axles that were contaminated during shipping, didn't matter, we change the oil before tests as a control, but guys were baffled when axles came in with bad oil. Come to find out they had been shipped on open flatbeds, without vent tubes installed, or even rattle caps. The factory shouldn't have that problem, but then again, they'll just put oil in the axles without checking if they are contaminated.

Zarthur

I put my Magtech cover on with 75 miles on my truck and it was white in color ,but it was not water I think it was some kind of break in oil.

Spooler

Has been stated a many a time on here. They apply a coating to the ring and pinion when the rearends are built to prevent rust and such when stored with no fluid. During the first break in 15,000 miles the fluid will look a nasty gray color. All is normal, that is the way it is supposed to look for the first fluid change.

Need95-00CTD

Spoolers right, its just gear grease, used to set proper gear tooth pattern on the ring and pinion... Never seen any diff with enough to change the oil color, but I guess AAM does things differently.

1-2-3

It's in a TSB from Dodge. It's from the assembly/setup procedure. This is quoted from part of that TSB:

"The cause of the milky-like appearance to the axle fluid may be due to the use of a white color gear marking compound during the axle assembly process. Axle gear marking compound is used to verify correct ring and pinion gear alignment during manufacture. The 9.25 inch rear axle is assembled on two different assembly lines. To visually distinguish axles from each assembly line, one assembly line used a white color gear marking compound (versus yellow). Half of the axles that were assembled during the above time frame may have the white gear marking compound mixed with the rear axle fluid. The white color gear marking compound is no longer in use by the axle assembly plant."

This is from the header of that TSB:

NUMBER: 03-02-00

GROUP: Axles

DATE: Mar.03, 2000

SUBJECT:
9.25 Axle Gear Marking Compound Causes A Milky-Like Appearance To The Axle Fluid

MODELS:
1999 - 2000 (AB) Ram Van
1999 - 2000 (AN) Dakota
1999 - 2000 (BR/BE) Ram Truck
1999 - 2000 (DN) Durango