07 Denali Tow/Haul shifting issues

[chevyguy04]

Have an 07 denali awd, has anyone had shifting issues while towing?

I notice while I am towing anything from 1000 lbs to 6000 lbs, in tow/haul mode it doesn't seem like its shifts right. When accelerating gently, in first couple gears it revs up real high and sometimes in order to get it to shift I have to let up on the gas. Also while driving when I step on it it seems like the transmission is confused and with either stay in the same gear, or it will hesitate and finally down shift. Maybe its just how the new 6 spds function, but my 02 denali towed like a breeze compared to the 07. I do a lot of towing in an 06 chevy 2500hd, and the denali just tows so much different.

When I had it at the dealer for the washer fluid recall, I told them about it, and asked if there were updates for the transmission and they said no but there was an update for the transfer case. Warranty is almost up, so if something is wrong i'd like to get it taken care of.

 

[Poncherello]

I find the 6 speed tranny searches very often for the proper gear. The 03 and 05 I had shifted much less often. I was a little surprised at how often the 6 speed in my 2010 shifts when under any kind of load.

 

[m332is]

The manual says use tow mode for heavy trailers. I pull my son's enlcosed alum go kart trailer (same sized as a snow mobile trailer) and found it works better w/o using the tow mode. Especially when decelerating... it doesn't have the hard/quick downshifts that out you through the windshield.

I'm probably pulling 1-2 thousand pounds at most.

Vince

 

[NJ Denali]

Tow mode has high shift points for more power. It also downshifts hard for better breaking control. I use it with heavier loads only.

 

[chevyguy04]

The problem with mine is it doesn't always shift, I have to let up and tap the gas to get it to shift, the only time I've had to do that in other trucks is when I am towing a heavy load, heavy being around 8 - 10,000lbs with 3/4 and 1 ton trucks. It must just be something with the 6 speed, not a big fan so far.

 

[NJ Denali]

That's typical with mine too, but when it hasn't revved high enough to shift. I holds the gear until it's ready to shift or until you tap it.