Pulling my approx. 7000lb. TT with my 06 LBZ, I find that if I want the truck to go to 6th gear while cruising down the road a 55MPH, I have to turn the Tow/Haul mode off, let it shift to 6th and then re-engauge the Tow/Haul. When I do this, the truck is happy to be in 6th and cruises right along with next to no hunting for another gear. Is there any possibility that I am harming the trans. in any way by doing this? The outside temps. were about 85-90 degrees and the trans was running 165 and coolant about 190-200.

My truck does the same thing. I usually don't use the tow/haul mode unless I am going up or done hills, it just seems to like it better without. And no, you should not be harming the trans if you let it sit in a higher gear.

I do exactly what you are doing with my 6,000 ty. You should be fine.

Thanks guys!

I tow heavy in kalifornia (55mph speed limit towing) and just accelerate to 63 or 64 and allow the trans to shift into 6th (all while in tow/haul mode), then back off to 55 or 58 and it stays locked up.

Mine does the same, I was just getting ready to make a post with the same question.

Just towed 7500lbs over Colo mtns last weekend, used tow haul the entire roundtrip. Used manual gear selection mode on steep climbs and all descents. However, my tranny had no problem finding and staying in 6th gear on the relatively flat sections of highway on its own in "D" with tow/haul mode engaged.

In those areas in D and 6th gear I was maintaining 65mph with cruise control and under 2000rpm. Awesome truck.

tow/haul raises the upshift points, as far as I know it doesn't touch the downshift points. When I tow I use it, set the cruise, turn it off to shift into 6th, then back on..

I heard the 6 gear which i guess is like overdrive gear is bad to tow in is this true... thats why it normally dosnt go into 6 with the tow/haul button on??

at 65 on flat ground, it will be in 6th tow haul or not.

it will not shift into 6th untill 63 mph when in tow haul mode empty or loaded with light pedal. it will not hurt the trans the truck is smarter than you if it needs to down shift it will. and the purpose of tow haul mode it to heep the truck in the torque curve and lock up the converter in the lower gears to help heep the trans cool.

Only thing you need to watch in the tranny temp. DOn't exceed 200 deg.f.

remember you have a dmax

if you watch the shift point into 6th is about 60 got 32ft 13k set on cruse at 62 and set back and take nap make the run to alaska up and back no prob