I have a 2003 Sahara w/124k on the clock.. I had my trans fluid changed out about 1 year and 10k ago.. I recently put a drake aluminum rad on and had to add trans fluid due to loss when installing the trans cooler lines. I topped off the trans and checked several times since replacement and everything seems well, shifts fine and all.. I did notice I have a coolant leak in the new radiator, possibly the drain plug but that's another issue. This past week.5 I noticed a whining noise at lower speeds, kind of low pitched, sounds like a power wheels motor pulling when the battery runs down.. I hope it's not the transmission. Is anyone familiar with this condition.. Could it be my transfer case needs fluids changed?