Class C downshifting ?

[jstrong499]

When auto towing with our Ford 450 class C and climbing a slight to moderate hills, the coach downshits and revs really hard and it drives me nuts. Makes me wish the Coach was a manual shift, then all this will go away. Any thoughts or technics beside adding throttle prior to climbing the hill.
Like to hear folks dealing with the same thing
Thanks,
Jamie

[T18skyguy]

Mich F wrote:
With cruise control on, the only way it can keep the speed up ( or at least try to keep it up) while climbing hills, is to down shift. The easiest/simplest/cheapest way to minimize that, is to disengage the cruise control on hills. 😉

x2. Cruise control for the flat lands only. When it get hilly cruise off and tow haul on. I leave tow haul on all the time hauling or not.

[Chum_lee]

NEWSFLASH: Every vehicle has it's built in limitations usually based on price point. Hopefully, someday (before you die) you guys will realize that you are a lot better off buying the vehicle/RV you need rather than building/modifying the one you have into the one you wish you had.

Although they're not perfect, if it was reliably possible, he engineers at Ford would have already designed the vehicle you wish you had at the price you can afford.

Chum lee

[Hank85713]

Jamie the 5 star is just a tune and the install instrument has the ability to diagnose and read trouble codes. You download the OEM code to the instrument then upload the tune via the under dash OBD plug. Its the rectangular one with about a dozen pins in it. I have the tune on my 2012 winnebago aspect, does civilize things as far as the rpm and transmission is. ALso helps with the dead throttle that they now have installed. You know its an electric thing and not cable or linkage activated, so now I have somewhat better throttle control with the tune. Ther may be a holiday sale coming up I dont know. I got mine when there was one and saves some $$. Mike does help if you have issues. Good guy.

[theoldwizard1]

Mich F wrote:
With cruise control on, the only way it can keep the speed up ( or at least try to keep it up) while climbing hills, is to down shift. The easiest/simplest/cheapest way to minimize that, is to disengage the cruise control on hills. 😉

On my 1998 E150 instead of disengaging the cruise control I would just turn off the overdrive as soon as we would start to lose speed going up a long hill. This would force it to downshift early, which was not a harsh and the engine did not rev up nearly as much.

[carringb]

docsouce wrote:
I have a smaller 2016 Class C 25ft oal and no slides and no tow. It's on an E350 chassis With the Triton v10. When I hit a long, short up grade, even a moderate/strong headwind it will downshift.Cruise on or not. I was going West across northern Texas on Rt 82 this last summer and the best speed I could get was 60 mph due to a strong headwind. Every time I finally got it going 65 or so and it finally upshifted the wind would slow it down it would downshift. I had the same problem last year heading West on Rt 2 in North Dakota. Very frustrating. I felt I was beating on the drive train so I just backed it down. Lived with it. These class C's aren't very aerodynamic. I had a 2008 F350 with the 5.4L engine that did the same thing. When the warranty runs out on this RV I might mess with the tuning. Well see.
Just thinking about this again.. If I leave it in cruise and it downshift it stays in the lowergear increasing speed well beyond where I had it set. If I knock off the cruise when I hear the engine load increase I can hold off the downshift longer and it will upshot sooner,then engage the cruise again. Hope I explained this ok.

Just use tow haul, and let in stay in the lower gear it wants to be on. Or manually put it in 4th. 5th and 6th are both overdrives on your transmission.

[Sam_Spade]

jstrong499 wrote:
By whats been said, it sounds like the 5 star tuner may be worth the $400 it cost. Is it much to install? I assume you’d like to have it close by if it shows you your motor dianostics ?
Jamie

It "installs" new firmware to the engine control computer, then you disconnect it, unless you want to use it's scan tool functions on an ongoing basis.......but leaving it connected when the engine is not running might drain your battery.

Installing the firmware is easy.
Un-installing it is too.

[jstrong499]

By whats been said, it sounds like the 5 star tuner may be worth the $400 it cost. Is it much to install? I assume you’d like to have it close by if it shows you your motor dianostics ?
Jamie

[Jayco-noslide]

My Class C is older so it only has a 4 speed trans but that doesn't change much. What I do is anticipate the hill and tap the brake pedal to kick off cruise control than I push the button to shift it out of 4th gear to 3rd and as it gets down to around 40 I back off the accelerator and manually shift down into 2nd. This eases the abruptness of the down shift and I have better control over RPMs. However reving doesn't harm the engine up to 4500 to 5000 rpm's(wish mine had a tach) and that's what it does to make power.

[Mich_F]

With cruise control on, the only way it can keep the speed up ( or at least try to keep it up) while climbing hills, is to down shift. The easiest/simplest/cheapest way to minimize that, is to disengage the cruise control on hills. 😉

[docsouce]

I have a smaller 2016 Class C 25ft oal and no slides and no tow. It's on an E350 chassis With the Triton v10. When I hit a long, short up grade, even a moderate/strong headwind it will downshift.Cruise on or not. I was going West across northern Texas on Rt 82 this last summer and the best speed I could get was 60 mph due to a strong headwind. Every time I finally got it going 65 or so and it finally upshifted the wind would slow it down it would downshift. I had the same problem last year heading West on Rt 2 in North Dakota. Very frustrating. I felt I was beating on the drive train so I just backed it down. Lived with it. These class C's aren't very aerodynamic. I had a 2008 F350 with the 5.4L engine that did the same thing. When the warranty runs out on this RV I might mess with the tuning. Well see.
Just thinking about this again.. If I leave it in cruise and it downshift it stays in the lowergear increasing speed well beyond where I had it set. If I knock off the cruise when I hear the engine load increase I can hold off the downshift longer and it will upshot sooner,then engage the cruise again. Hope I explained this ok.

[jstrong499]

Thanks for all the inputs, and yes its running on cruise when all this happens. I have no problem slowing down going up hills, but the downshifting is anoying to say the least.

[harley-dave]

Desert Captain wrote:
The {late model 2 valve} V-10 makes max torque of 420# at 3,250 rpm and max HP of 305 at 4,250. You can run at 4K+ all day without harming that beast of an engine but you will burn a ton of fuel.

At max torque of 3,250 my fully loaded C, towing my motorcycle in the 10' cargo trailer (bike and trailer weigh 2,220} will climb almost any 6 percent grade at 55 without excessive noise and with reasonable mileage {been averaging 9ish for years}. Rare indeed is the 6 percenter that lasts more than 10 or 12 miles so you will be over the hump so to speak, in just a few minutes.

Tow haul is your friend and unless you're running very light, on the flat or a slight downhill you should utilize it for optimum performance as it resets the shift points. On steep downhills, it provides engine braking without burning a drop of fuel, saving your brakes. It also will keep your transmission 12 to 20 degrees cooler extending its life.

To get the best out of this fine engine just put your foot in it as needed and use your Tow Haul.

:C

X2 We also have the 5 star tuner and its made a very large difference. We routinely tow a 3200 lb. car or 2 Harleys on a trailer and the RV gets a workout. Easy 55-60 MPH up those grades unless a truck/traffic slows us down. Also improved the shifting. Just as aside we also gained 1 MPG.

Dave

[Desert_Captain]

The {late model 2 valve} V-10 makes max torque of 420# at 3,250 rpm and max HP of 305 at 4,250. You can run at 4K+ all day without harming that beast of an engine but you will burn a ton of fuel.

At max torque of 3,250 my fully loaded C, towing my motorcycle in the 10' cargo trailer (bike and trailer weigh 2,220} will climb almost any 6 percent grade at 55 without excessive noise and with reasonable mileage {been averaging 9ish for years}. Rare indeed is the 6 percenter that lasts more than 10 or 12 miles so you will be over the hump so to speak, in just a few minutes.

Tow haul is your friend and unless you're running very light, on the flat or a slight downhill you should utilize it for optimum performance as it resets the shift points. On steep downhills, it provides engine braking without burning a drop of fuel, saving your brakes. It also will keep your transmission 12 to 20 degrees cooler extending its life.

To get the best out of this fine engine just put your foot in it as needed and use your Tow Haul.

:C

[Sam_Spade]

DrewE wrote:

Some people here have put in four star tunes and reported good results; among other things, they can tinker with the shift points some.

I did that and it helped with the downshifting some.
But when it stayed in top gear and pulled hard, the engine vacuum went down enough that the A/C air flow got squirrely.