Sorry I didn't mention this earlier, but was in short supply of time when making the previous post. Make sure you're parked on smooth, level ground when checking the transmission level. The 4L30E doesn't have the handy dipstick, so you have to get under the vehicle and remove a recessed bolt to see if any dribbles out. Kinda screwy, but that's the way of GM who builds that transmission. Make sure to have a catch pan when checking and look in the CD shop manual for the procedure.