Yes, your 08 auto does have overdrive. I am not trying to be a typical media type fear monger here, I just make it a point to try to make people understand that having an auto in overdrive while towing on hills or grades can cause a problem over time. The overdrive is not the problem, it is the truck's computer actually that will send the transmission into a hunting fit, back and forth between direct drive and over drive on a hill as it is trying to match it's idea of the correct speed. The hunting back and forth between gears is what builds the heat in the trans, the heat is what breaks down the transmission fluid, the broken down trannsmission fluid is what causes the transmission damage. So as long as you pay attention to what your truck is telling you, and if it starts hunting you take it out of overdrive, then you'll be fine. (This is all covered in more detail in the towing bible and many other posts in this section)
However, the reason I was so absolute about it is because the opening post asked about towing in the mountains, not about small grades or little hills. In the mountians you can be assured that the tranny is going to hunt, so in the mountains don't even give it a chance to do so and just drop to direct drive, which will also give you more engine breaking ability on the downgrades.
Originally Posted by awoit
does my 08 access cab have auto overdrive? cuz now im scared to pull anything up a hill