T-Case Fluid Is Blue???

biketopia · 11-01-2009, 01:17 PM

I did an oil change the other night and took the opportunity to check out the diffs and T-case for the first time since I got the truck. Every thing seems normal and very clean except for one thing. The T-case fluid is blue?? It seems to be some sort of oil, just don't know what. The only other blue oil I know of is John Deere, they dye the 15w40 they use for hyd fluid in there new back back hoes. Any ideas?

**ob_1jr** · 11-01-2009, 01:20 PM

someone put autotrac II fluid in your transfer case. By GM it is supposed to be tranny fluid. The Autotrac fluid wont hurt, but its not what is recommended

**Hondarider552** · 11-01-2009, 01:20 PM

The only thing I can see being blue is autotrack fluid.. I know motorcraft rear end addative is blue..

drain and refill with 5-30 motor oil.

biketopia · 11-01-2009, 05:59 PM

why 5w30 over ATF?

**Hondarider552** · 11-01-2009, 06:02 PM

Quote:

Originally Posted by biketopia

why 5w30 over ATF?

ATF will evaporate when motor oil will not. doesnt harm your tcase, Mike L preaches to run it and my 4wd engages/disengages smoother than it ever did.

K9Duramax · 11-01-2009, 07:53 PM

and don't forget that the AUTOtrak is expensive as all get out!!!!!!!!!! Just as well put liquid gold in there... lol

**ob_1jr** · 11-02-2009, 12:49 AM

yeah the 5w30 write-up said to overfill with 3 quarts through the speed sensor. I did this. I havent had any problems yet.

DeereMan · 11-04-2009, 11:07 AM

I seem to remember reading an article about this. Let me see if I can find it.

RedBowTies88 · 11-04-2009, 11:10 AM

Quote:

Originally Posted by DeereMan

This has been a widely spread rumor for a while now but no one has yet come up with any proof that the ATF is actually evaporating. The suspision is that it is more of a maintenance (or lack of maintenance) issue. Fill the transfer case with synthetic ATF if you have any doubt.

when i changed to motor oil i had a tiny bit over 1qt of atf in there....

its proven 5-30 is the way to go...all the big boys racers and pullers use it

**bigdaddydiesel** · 11-04-2009, 11:35 AM

I agree, I have only heard good things about 5w-30 syn in the transfer case. There are many tranny builders nationwide that are swearing by 5w-30 syn in there...