Who knew about this? Why would my Tow/Haul setting shift into OD. It's only use is turning off the MDS. It shifts into OD at a weird spot too.
I would get up to speed and it would hold 4th for a while and finally go to OD. I mean if you are going to give me OD, let me use it...

How do I know you say? Well, when I realized I was doind 70 at 1500 RPMs pulling 6000lbs, I thought to myself, this is nice.

Then I hit the button to go from Tow/Haul to OD Off, and the dang thing shifted down. Tried it a few more times and if shifted out of OD every time.

 

Tow/haul mode holds out for a long time because if you are actually towing something, it's more practical than an immediate shift.
The reason your truck downshifts when you go from tow/haul to OD off is because OD off locks out Overdrive. Therefore you won't be able to have that gear no matter how many times you hit the button.


Found this in a search.

"TOW HAUL” mode, 5th gear (if equipped) is disabled
and 2-3 and 3-4 shift patterns are modified. Shifts into
Overdrive (4th gear) are allowed during steady cruise
(for improved fuel economy) and automatic closed throttle
downshifts to 3rd gear are performed (for improved
braking) when driving conditions warrant. Pressing
the “TOW HAUL O/D OFF” button a second time to
select O/D OFF will disable 4th and 5th gear completely,
which should eliminate any excessive transmission shifting."

btw...4th gear and 5th gear are considered overdrives in these tranny's.

 

I figured that out driving it. the shift point is highly annoying for the OD while in TOW/HAUL. Keeps me at 3000RPMs way too long, once I've reached speed.

I figured it out on the way home an managed to feather the throttle and keep it in OD most of the time, but on the way down, it was really ticking me off.


That's good information though.

 

My 2007 has 3.55 rear end

My 1998 had a 3.90 rear end

Didn't think that would make much of a difference but the 1998 pulled at a lower RPM with OD OFF.