Yep, that's usually what you hear although somebody might show up to say gear oil is ok in the NWC transmissions. And they probably won't be mistaken, but it may depend on where they live. ATF according to everything I've read will cause slightly more wear on bushings, bearings, etc but we're talking tens of thousands of miles. Gear oil might make it wear a bit less but will make it feel pretty sluggish in cold weather.
