I have a 2005 3500 4x4 with a 4. 10 ratio that I occasionally use to tow my toy hauler 5er. Jim Anderson suggested I do a computer reflash TSB # 21-006-07. Has anyone done this and what will it change when the tow/haul mode is selected ? If I'm correct it will lock out overdrive when activated. I don't want my rpms to change as I like to stay in the 1900-2100 range while cruising @ 65 mph. A thorough explanation would be appreciated. I'm hesitant to do a computer reflash as there is is no reversing it. I made the mistake of doing the deal where the horn blows with the door open while the transmission is in gear. Tough to back into a campsite without sometimes hanging out the door. If you're dumb enough to fall out, oh well ! Thanks for your help.