04 Tahoe calls for AutoTrak ll fluid in transfer case. Stuff's BLUE, and 17 dollars per quart. Looks, smells, pours, and feels a LOT like Dexron ATF.
.
Think the BLUE stuff is necessary, or any better ?
Will I grenade the transfer case if I fill it with ATF ?

 

It's not the same stuff, it's made for the transfer case only.

The AC Delco website does not suggest mixing in any other fluid.

Transfer Case Fluid: Auto Trak II | ACDelco

 

My local Transtar sells autotrack II fluid for $8 a quart. I grabbed a few for myself. You can find it online for around $10 a quart shipped. Valvoline makes a "multivehicle" transfer case fluid that says it is 100% compatible with autotrack II fluid as well. $9 a quart at your local parts store.

 

For sure different stuff. We sell the AC Delco transfer case fluid at the store I work at.