I have an 07 Dodge dually with 5.9L and automatic tranny. It seems worse when it's hot outside and may not even do it at all in cooler months, but when running highway speeds, 70+ MPH, in the warmer months it will kick in and out of OD and sometimes the tranny temp light comes on and dings. When it does this the Tow/Haul and OD Off indicator in cluster changes. Of course it's cooler now, but getting ready to tote toy hauler to Arkansas from Texas and take it to tranny shop and they see no codes and it's shifting fine. Thoughts?