Hey guys. I changed my axle bearings and seals as you probably saw in the other thread. The gear oil was pitch BLACK and looked dirty---the way I figured it to look given I have 141K and its probably factory fluid.

I just changed my FRONT diff and the fluid was all creamy BROWN....kinda like coffee with a lot of cream in it or even the color of carmel. Is this normal?? Did it have water in it? I have had NO leaks on the front diff prior to the fluid change tonight.

For those that are interested: It took about 2.5 Qts....probably only takes 2.25 but from the leaks from the fluid pump gun I probably spilled about .25 qts. I used Royal Purple 75w90.----DirtySCREW

 

that creamy coffee color is from water or moisture mixing in with the oil.

 

Do you think my gears are ok??? I'm worried now! ---DirtySCREW

 

They should be okay. This isn't uncommon.

 

they should be ok. the important part is that you found this NOW instead of when something started to make noise in the front diff or worse case gave you an inspection port there all of a sudden. change the fluid out of there and keep an eye on it. make sure you dont have any leaking gaskets or seals allowing water in. make sure your breather is not broken as well.

 

I would also check to make sure the vent is properly routed so that water can't be sucked into the front diff.

 

When I changed my front gear lube, it came out just as you described.. I put in Amsoil front and rear at that time and went several years with that.. I had to change out the rear diff fluid for an axle seal leak and changed it all again and used Royal Purple this time around.

When I drained the front this time around, it looked fine, so I've not worried about it.

I've got 212,000 miles on the truck, and the 4x4 works fine so I don't think anything is wrong..

Mitch

 

Thanks guys, I feel a little better about my baby now.
Mitch--I used Royal Purple in my diffs as well. Funny cause I'm looking at probably Amsoil for the tranny and transfer case---DirtySCREW

 

I was going to go with the Amsoil again, but I saw and heard about RP, so I decided to give it a try.. So far so good!

I just run regular trans fluid.. Actually, I just get the gallon jugs from Walmart that say MERCON/DEXTRONIII. I put a drain on my trans pan and I drain it and add new every other oil change, so it just keeps fresh fluid going thru it, even though it's only 6 qts at a time, I like doing that then letting the same fluid just ride along for 30,000 miles... But, that's just me...

Mitch

 

Another possiblity is that your diff got the pattern checked at the factory. Supposedly Ford pulls diffs off the line at random and runs a contact pattern check with gear marking compound. They leave the compound on the gears then they get assembled and sent out that way and the gear compound makes the gear lube look just like it has water in it.

 

Thanks Ray----that is interesting. Is there any codes or markings anywhere to signify that Ford randomly pulled the particular diff? Just curious. At least now I know it has quality fluid in it now.---DirtySCREW

 

If there's a way to tell it was checked I don't know what it is. You see painted dots and that sort of thing on subassemblies like differentials sometimes so maybe something like that? I ran into the milky front diff once changing fluids on a brand new truck and was told the pattern check story by our diff guru at the dealership.