changed diffs and tcase

[ness5575]

changed the fluids in the front and rear diffs and the transfer case yesterday.

this is the second time that I have done the front differential, and both times the old fluid had a whiteish tint to it. not like the dark black that comes out of the back diff. is that normal from the front diff?

 

this is my first t.c. change (the first was done under warranty to change from the red to the blue autotrac 2). is it normal for this fluid to turn black? i was expecting to drain blue fluid out and was surprised to see it come out black.

 

thanks for any help!

[concours]

White gear oil has been contaminated with water and is emulsified. Check your vent line, much water fording? I don't know about black autotrak II fluid, I just put in some fresh blue myself.

[ness5575]

i have never been thru deep water.

does the vent line come off the top of the differential? is it just a plastic tube of some sort. just so i know what i am looking for...

[foghorn23]

As far as the t-case goes, when I changed mine at about 25K it was black. Made me feel good to see the smurf oil replacing something that looked that bad. I assume it was normal as I've had no problems in the 15K miles since. Changed the rear diff a couple of months ago, but no white, so no help here. Good luck

 

Vroten

[Butch 02 Denali]

No white in my diff oils at 5k miles. My transfer case (red)

oil came out silvery tinted (alum) and I put Mobil 1 back in. That was also at

5k miles. I'm now at 17k miles and about to do the TC with GM blue, I'll let you know!

 

There was a TSB on the plastic fitting for the vent on the diffs, something about black or white plastic and one of them let water in or leaked diff oil. Anyone got that?

 

Butch 02 Sierra Denali