transfer case fluid

I have a 99 Burb with the automatic transfer case which we recently changed the front and real seals on the transfer case. The fluid that was in it was red so we topped off the transfer case when done with ATF. However, after doing a little research, it appears that it takes a special fluid (Autotrak II), which should be blue. Will topping off the transfer case with ATF hurt? Should I drain the transfer case and fill with the Autotrak II fluid? The guy who did the work says it won't hurt anything in the transfer case????

Thanks.

The Autotrak II is what GM now recommends. The red stuff was most likely put in at the factory.

If you just had the seals replaced you should replace the fluid as well. The new blue stuff is supposed to perform better under high temps. At $4-5 a qt. it is not very expensive to replace and worth it in the long run.
Tim

From reading my owners manual of my 99,I believe that ATF is used in manual shift transfer cases.On the transfer case it may recommend dexron III,but I phoned the dealer to clarify,and they recommended the auto-trac II oil.I asked if it was a synthetic oil,but they couldn't tell me.I tried to cross over the oil at the local parts store, but there was nothing available.I also changed the front output seal and changed the oil.Auto-trac II was in there,so I replaced it with the same.There must be something special with this oil because of the auto mode of the transfer case.Other than that it would function like a regular transfer case.
chuck's