Tow/Haul mode questions

[aknomad]

I recently switched to an '06 6.0L after having an '02 7.3 for 4 years. I tow a 10K fifth wheel most of the time. The change was to go to a dually, with plans to be able to tow a bigger trailer later on. Both trucks were 4x4s.

When using the Tow/Haul mode in the new truck, I find it downshifts one gear when I tap or use the brake, but if I need more brake further down the hill it downshifts again, causing the engine to rev really high. Called Ford and they say there's no true redline for this truck, that the engine management systems will prevent over revving. Can I trust the brain of the engine to not let it hurt itself?? Or should I "manage" it myself, turning off the Tow/Haul and back on again as I'm going down a hill?

Appreciate any advice you've got!

 

[Kleetus]

I'm thinking the limit is about 3900 rpm. That's turning don't get me wrong, but it does work well at that speed for braking. I would have to think that if one of these engines went boom from overspeed on a hill, we'd have heard somebody talk about it by now.

Let her fly.

 

[powerboatr]

ummm it will disengage the tranny before you over speed the engine
the bad part is now your freeeeeee wheeling
our first run scared me
I was doing 65 ish, tapped the brakes to slow down on the mountain, it dropped to 4th and rpm was way up near 4k just a signing but slowing down
but not fast enough and i applied brakes some more and pulled us down to 50 or so and she dropped to 3rd ZING rpm back up to 4k
real smooth sounding to
then we were at the bottom and it up shifted to OD and we tooled on down the road
this was a 600ish foot drop over 1.6 miles gps.
snaky curves and all, guard rails are more like correction devices to ensure you slide down and not over the mountain

it is designed though to unhook and save the motor.
i was impressed

Uh houston we got a problem of double posting again , honest it wasnt me this time

 

[lvtitan]

yes it is supposed to do that. it is a godsend and really saves the brakes.