When you pull in the mountains, do you always use "tow/haul", or do you put the trans in "M" and shift accordingly. I'm headed that way soon and not sure whats best for the truck. My 5vr is 10K @ 29' long. The truck is a F350 6.7.. Thanks

 

I'm not Rick or a fiver owner but put it in T/H and let the truck do it's job.
I think T/H mode is great on this '11 truck.
You still have the option of locking out gears if you need to make a quicker decision than the computer without changing to manual mode.
The 6.4L doesn't have manual mode and it works just fine with the exception of less MPG.

It will be interesting to read what others do, though.

 

yes use the tow-haul, I have a 2010 40ft fiver, Gigger

 

Don't have my Ford yet, but on my GMC I always use tow/haul

One of the several things tow/haul offers is the locking of the converter in 2-6 gears.

This:
helps keep temps down as the torque converter is not "torque converting"
helps keep the engine in the peak torque range
helps the engine braking feature be more effective by keeping the converter locked (think manual trans)
raises up and downshift points to minimize "gear hunting"

 

Like the above post I put mine in T/H.
I don't have a 5er, But I do pull my gooseneck 4 horse trailer ( around 13,000lbs) thru a lot of mountain passes.

With it in Tow/Haul and the Drive position, I then just use the button on the stalk to downshift if I need more engine braking or upshift when I'm down with a downhill stretch. I have not used the "M" on the pavement.

About the only place I think I would use the "M" is starting out in Snow or Mud where I might want to start in 2nd and avoid 1st to prevent spinning. Or creeping down a rough offroad where I want to keep the RPMs up but the speed down.

 

I just learned something new, no surprise. I thought the +/- on the shifter was for "M" only. Didn't know you could do that in "D". Thanks

 

With my 2005 6.0 when the 13000# 5er is hooked up its in tow haul and will be doing the same with the 6.7 I have ordered!!!

 

All that it really does in D is allow you to command a downshift and/or lock out shifts above a certain gear. In M you can manually shift up and down and it will (within reason) stay locked in the gear that you select.

 

Here I am... working today...You have received good information so far. I have pulled several long 8% and 9% grades with my new truck. I use tow/haul when I have my fiver hooked up. It works automatically with the integrated engine brake. When you crest the hill and begin the descent, just tap the brakes to engage the engine brake. If you desire more engine braking and a lower descent speed just tap the brake again. Each tap results in a 10 mph drop in speed. I am very pleased with the way the system works.

Regards

 

Well, learn something every day. I didn't know it works like that.

--
gordon

 

Yes, and the dealers have no idea how the thing works. I have a funny feeling that when Pickuptrucks.xxx did their shootout, they had no clue either. Too many people getting bent out of shape because there is no dash switch. I like the "foot switch". I have descended 3 miles of 9% grade and never applied the brakes except for the 2 taps for the engine brake.

Regards

 

The times I don't use T/H when pulling the trailer:

If I am on a highway, relatively flat, and not traveling at a high enough speed to auto shift into six, I will disengage T/H for a few seconds in order for the trans to up shift.

 

Duane,

I actually do the same thing. It seems like the trans will not go to sixth when I think it should.

 

I use "M" almost all the time, except in hilly terrain. I agree with the above, use "D" and T/H if you are in the mountains. System works great but when I tow heavy, I make sure I am only going 50mph before I start the descent. Your rv is not quite heavy enough maybe to push you past the capability of the tow/haul mode strategy, if you were another 2 tons heavier, you would need braking even if you started your descent at 50mph. I know I do.

 

Actually looking forward to having 18,000 pounds pushing me down the hill to give it a whirl