Ok correct me if you would. The way I understand this is if I choose
TOW/HAUL mode: I get all gears even overdrive at a little higher RPM. Is thiscorrect?
and if I select to cut out the
OVERDRIVE, No overdrive but do I get a little higher RPM as well? [&:]

Oh yeah this is on my 07...

 

that should be the way it works. the trans will shift a bit later/firmer to help in moving the load. locking OD out is good if you have an exhaust brake or if your pulling some hills and the tranny is constantly shifting in and out of OD.

 

or going down a trail in 4x4 low. 2nd gear was too low, 3rd was just right... if it will hold it (mine doesnt, it upshifts... no 3rd switch position)

 

TQ lockup is earlyer in tow/haul also

 

Exactly....the TC locks up in 3rd gear, rather than wating until 4th. It also locks up 4th gear as soon as it shifts. The shifts are much firmer and are usally held longer. For instance, it won't shift into 4th gear until you are either A- above 45 MPH and not on the throttle hard or B - you turn on the cruise control.

 

My understanding of it, is that tow/haul is underdrive? My '05 has tow/haul, but it increases the RPM's, so that's a more simpler way of calling it underdrive?

 

I don't think your '05 actually has the Tow/Haul mode, I think all it does is lock out the OD. On the 06 trucks, you have Tow/Haul and OD lockout.

In T/H, it modifies the shift points, pressure, TC lockup and the actual shift program. In the OD lockout, all it does is go up to 3rd gear and locks your TC.

 

05 doesn't Lock out the OD just makes wait to lock up

 

i run my truck in tow/haul most of the time....i live in very mountainous areas and it shifts up and down alot and in tow/haul it seems to do alot better..........is it bad to run in tow/haul alot?????????

 

wont hurt a thing