I have a 2003, CC DRW 6.0 litre, 4.10 gears. I towed my 9000 lbs Jayco trailer for the first time today , just a short distance though. The tow haul mode really seemed to gear the truck way down, I tryed it without the tow haul and it seemed to handle it beautifully. Will I hurt the transmission by not using the tow haul mode when towing? Am I right in expecting the my fuel milage would be much less while in teh tow haul mode?

 

I dont think you will hurt the trans. I think it works great in tow mode. With 9K I would use it.

 

Yes, use it, that's what it's for plain and simple, 9000 lbs. is alot, you are more than doubling the weight of your truck, just push the button and use it. The ONLY time I would pull any major weight and turn off the tow/ haul is cruising on flat ground on the freeway just to save fuel basically.

 

The TorqueShift Tow/Haul mode does not change your gearing.

What it does when accellerating is prolongs the time in which it will upshift to a new gear. By doing this, it greatly reduces the number of repetitive upshifts and downshifts, which creats a lot of heat and could ultimately grenade the tranny.

On deceleration, it locks the torque converter to better slow you down by taking advantage of engine breaking.

Personally, on accelleration, I only use Tow/Haul about 30% of the time, and when I do use it, I turn it off when I hit cruising speeds. I have it on 100% when going up a long and steep hill. I use it 100% when stopping, to save my brakes as much as possible.