If the transmission is frequently shifting Overdrive-Direct-Overdrive-Direct-etc.,I push the button.
If the transmission is cruising along in OD without shifting up and down, I leave it in OD
In other words, if the computer can't make up its mind what gear to be in, I tell it to stay in Drive. When the computer knows what it is doing, I allow it to do what it is supposed to do.
If I were rich, I would have a custom built motorhome on a Dodge Ram 4500 chassis, with a 6 speed manual transmission that I could control as I see fit!
Then I wouldn't have to put up with an idiot computer!
CM1, USN (RET)
2002 Fleetwood Southwind 32V, Ford V10
Toad: 2006 Jeep Rubicon LJ
Other toad: '06 PT Cruiser, Kar Kaddy dolly
Toy: 1977 Dodge W100 CC SWB, 3/4 ton axles & springs
"When seconds count, help is only minutes away!"
mumkin wrote: OK... no laughing as most of you will probably think this question is... dumb.
This week I will likely head north from AZ and the weather looks good, so I can head up through Prescott and on to the Raton Pass. From reading a few threads (like this one) on the tow/haul button (something new for me), it seems that using it in the mountains is a good idea. I am not towing anything.
So, here is my question. Do I have to be stopped to push the button on or off? I would rather ask before experimenting. If I am driving along about 65 and see the mountains nearing, what happens if I push the button?
With Ford's 5-speed van transmissions (from 2005 model year on up) with TOW/HAUL engaged, overdrive still kicks in as needed - no different than with TOW/HAUL not engaged. As I understand it, the main (but not only) thing that changes with TOW/HAUL engaged is that when accelerating up through the gears below OD, the transmission holds each gear a bit longer to allow more engine torque to be available for heavily loaded vans by invoking higher engine RPM. When loading on the engine is reduced enough, OD kicks in as normal.
I don't know how Ford's van transmissions from 2004 on back behave. Aren't they only 4-speed and isn't their electric gearshift button labeled something else different from "TOW/HAUL"?
As far as "logic" would seem to dictate, a Ford cutaway van with a motorhome built on it pretty much constitutes a "heavily loaded" van all the time. IMHO, the jury is still out as to whether or not one should drive a Ford-based Class C motorhome 2005 or later with TOW/HAUL engaged all the time. The Ford operator's manual seems to be assumming that the vehicle that they're giving TOW/HAUL mode instructions about is a workaday delivery van - which is what the E-Series truck is designed to be.
I know my Class C certainly feels a lot more responsive and nimble with it engaged. This tells me that with TOW/HAUL mode not engaged, during acceleration or pulling up a hill my transmission is probably "torque converting" more .... in other words slipping more. Slipping is inefficient and theoretically wastes energy (gas).
I guess only careful long term gas mileage testing with the same Class C motorhome driven with, and without, TOW/HAUL mode engaged would prove conclusively one way or the other which mode is optimum for a Class C motorhome based on a 2005 or later Ford V10 cutaway van chassis (taking into account that the rear differential ratios are different between the E350 and the E450).
rvten wrote: No you do not have to be stopped to turn the TH on/off.
Thanks!! That's what I needed to know. I didn't want to trash the transmission on my new Chevy with only 4000 miles. (my previous GWV B was on a Ford with overdrive... Chevy has no overdrive, but the tow/haul button)
On a 6 speed chevy the last two gears are overdrives..at least on my 2010 they are.
But no lock up torque converter...least I'm pretty sure not.
When using T/H when you touch the brake it will shift down a gear also.
T/H does raise the shift points to a higher rpm ..will still hit 6th gear but like at 65 instead of 55.
Capt.Storm wrote: On a 6 speed chevy the last two gears are overdrives..at least on my 2010 they are.
But no lock up torque converter...least I'm pretty sure not.
When using T/H when you touch the brake it will shift down a gear also.
T/H does raise the shift points to a higher rpm ..will still hit 6th gear but like at 65 instead of 55.
I don't have the 6 speed (older platform)... not sure how much that changes your explanation. Presumably, I only have one overdrive gear but the rest is about the same.
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(my previous GWV B was on a Ford with overdrive... Chevy has no overdrive, but the tow/haul button)
