I ahve some questions on the 06 auto tranny. The first push of the selector button gives me the tow haul light and the next push gives me the overdrive light. After reading the manual it sounds like the tow haul allows different shift patterns and the next push overdrive allows torque converter lock up. I am not understanding any of this can anyone help. I am planning a long travel with my 9000lb trailer in March (first timefor everything diesel, this size trailer, and long travel with it all) and want to understand everything. I am going to post another question on braking this set up too.

 

I have an '04 2500 so may not have same mechanism. Mine just has tow/haul and i use it whenever the load (in the bed) or what I'm towing is significant enough to place some strain on the truck. The tow haul allows broader shift points and to my knowledge does not engage OD fully, since towing/hauling is hard on the OD.

 

I would say push it once and go. with 9K behind your truck you wont even know it is there