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08-30-2017, 10:21 PM
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#1
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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Towing steep grades
We have 2017 Thor Quantum 31-foot on Ford E450 with V-10. Towing 1999 Jeep Wrangler Saraha, 3,257 pounds. Drove from Phoenix to Show Low AZ - steep grades. Coach at times struggled to maintain 40 mph. Need advice. New at this. There is a trailer icon on shift lever with button at end of lever. Have option of 4th gear among others. Should I be doing something different than just leaving transmission in Drive and letting the coach struggle? And, how high can the RPMs safely go?
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08-30-2017, 10:35 PM
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#2
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Senior Member
Brand: Thor Motor Coach
Model: outlaw 37ls
State: Europe
Posts: 230
THOR #6831
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steep grade
yes, the torque peak is about 3200-3400 rpm for the v10. this is where the most power is at. shift your trans up or down to keep this rpm you will easily climb the hills, your speed may go down to 25mph no need to over rev motor. at very high alt. 10,000 the air does get thin so there will be less power, drive slow and steady and enjoy the view.
it will take some practice to get it right. if the engine temp get high , turn on the dash heater.
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08-30-2017, 10:46 PM
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#3
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Senior Member
Brand: Thor Motor Coach
Model: Hurricane 35C
State: South Dakota
Posts: 1,132
THOR #3761
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That button at the end of the shift lever is for Tow/Haul mode and it is designed to help both going up and down hill grades. It will change where the engine shifts to provide more torque and power going uphill and stay in lower gear going downhill to allow the engine to do much of the braking and not have to ride the brakes. When you press the button, a Tow/Haul icon should show on the dash.
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John
2016 Thor Hurricane 35C with pups Piper and Annabelle
2013 Ford Fiesta toad
FMCA - F457085
Blog - https://traversity.us
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08-30-2017, 11:14 PM
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#4
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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Quote:
Originally Posted by jpmihalk
That button at the end of the shift lever is for Tow/Haul mode and it is designed to help both going up and down hill grades. It will change where the engine shifts to provide more torque and power going uphill and stay in lower gear going downhill to allow the engine to do much of the braking and not have to ride the brakes. When you press the button, a Tow/Haul icon should show on the dash.
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That is helpful! I looked through the Thor owners manual, and it does not explain anything.
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08-30-2017, 11:15 PM
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#5
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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Quote:
Originally Posted by captmetal
yes, the torque peak is about 3200-3400 rpm for the v10. this is where the most power is at. shift your trans up or down to keep this rpm you will easily climb the hills, your speed may go down to 25mph no need to over rev motor. at very high alt. 10,000 the air does get thin so there will be less power, drive slow and steady and enjoy the view.
it will take some practice to get it right. if the engine temp get high , turn on the dash heater.
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Thank you for responding. The owner manual is not of much help.
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08-30-2017, 11:16 PM
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#6
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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Quote:
Originally Posted by jpmihalk
That button at the end of the shift lever is for Tow/Haul mode and it is designed to help both going up and down hill grades. It will change where the engine shifts to provide more torque and power going uphill and stay in lower gear going downhill to allow the engine to do much of the braking and not have to ride the brakes. When you press the button, a Tow/Haul icon should show on the dash.
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So, do you engage the button when preparing to climb, and disengage when back on level?
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08-30-2017, 11:17 PM
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#7
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Senior Member
Brand: Thor Motor Coach
Model: 2017 Windsport 29M
State: Indiana
Posts: 3,692
THOR #5196
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Quote:
Originally Posted by DLM1965
That is helpful! I looked through the Thor owners manual, and it does not explain anything.
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Information about the tow/haul mode will be in your Ford owners manual, explains it fairly well.
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08-30-2017, 11:21 PM
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#8
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Senior Member
Brand: Thor Motor Coach
Model: Hurricane 35C
State: South Dakota
Posts: 1,132
THOR #3761
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Quote:
Originally Posted by DLM1965
So, do you engage the button when preparing to climb, and disengage when back on level?
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Yes, pretty much. I generally use it for engine braking here in the east, not too many extremely steep hills that need it for climbing but I like to not have to use my brakes for a lot of downhill braking. Just tap the brake pedal and it downshifts to allow the engine to drag.
As SuperD stated, Tow/Haul is a Ford thing and should be in the chassis manual.
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John
2016 Thor Hurricane 35C with pups Piper and Annabelle
2013 Ford Fiesta toad
FMCA - F457085
Blog - https://traversity.us
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08-31-2017, 02:38 AM
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#9
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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Thank you
Quote:
Originally Posted by SuperD
Information about the tow/haul mode will be in your Ford owners manual, explains it fairly well.
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Thank you - very helpful.
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08-31-2017, 05:37 AM
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#10
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Site Team
Brand: Thor Motor Coach
Model: ACE 27.1
State: Florida
Posts: 14,117
THOR #7035
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Quote:
Originally Posted by DLM1965
So, do you engage the button when preparing to climb, and disengage when back on level?
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No, engage it when you are towing and/or hauling a load; which for an E450 RV is: All the time.
On my ACE the only time I don't use Tow/Haul mode is accelerating to highway speeds on the on-ramp. YMMV
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Ted & Melinda
2016 ACE 27.1
2016 Chevy Sonic Toad - Selling
2020 Chevy Colorado Z71 Trail Runner Toad
2024 Chevrolet Trax 2RS - Soon 2B TOAD
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08-31-2017, 06:38 AM
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#11
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Senior Member
Brand: DRV
State: Texas
Posts: 678
THOR #3109
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The Ford T/H mode changes the upper shift points on the Torqueshift transmission when accelerating, and helps with engine braking when going downhill. You should practice with it to understand just what it does and is capable of doing. When in T/H and beginning to climb a hill/grade, it will allow the trans to downshift earlier as you increase gas pedal pressure--the trans will climb the hill without the T/H mode, but will lose more speed before downshifting, which will end up having to add more throttle to make up the lost speed. When beginning the downside, pay attention to what is going on with the rpms/speed--when the trans senses you are gaining speed without pedal input, it will downshift one gear; if it keeps accelerating, it will eventually downshift another gear if needed. At any time, if you apply the brake and the T/H is engaged, you will probably note a downshift, maybe another if speed increases. Don't worry too much about the rpm increase--the V10 will take 5200 without damage.
Driving a MH of any size dictates that you learn the transmission gear changes/rpm differences and when they occur, and also learn to anticipate the approaching up/downshifts so they don't bother you.
If you have the 5-speed trans, you can note 4 shift points on the tach, and another rpm drop when the torque converter lockups on accelerating. If it is a 6-speed, then 5 shifts before the lockup. The T/H mode also keeps the torque converter locked up when decelerating to reduce need for brake usage. Try this: drive around town on flat roads in T/H mode--and watch what happens as you approach a stop light slowing down--you should note several down gear changes and associated rpm rises. Eventually it will drop to first gear if you have enough space to let the MH come close to a stop without the brake.
It is an interesting computerized transmission and you need to learn how best to use it.
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08-31-2017, 11:05 AM
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#12
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Senior Member
Brand: Still Looking
State: Texas
Posts: 6,187
THOR #2121
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Quote:
Originally Posted by DLM1965
.....cut.... Should I be doing something different than just leaving transmission in Drive and letting the coach struggle? And, how high can the RPMs safely go?
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What do you mean by "struggle"? High RPMs? Having to push down a lot on throttle to go up hill?
Your engine is rated at a maximum of 305 HP at 4,250 RPM, so unless you are in a big hurry, there is little to gain by going much beyond 4,000 RPMs in the first place, whether it's safe or not. Your ears will also thank you.
I personally go a step further. The V-10 engine in your motorhome is rated at 420 lb-ft of torque at 3,250 RPMs, which is 260 HP. Since that's 85% of maximum power, I rarely go much above 3,250 to 3,500 RPMs climbing long grades; unless in a big hurry for some reason.
Tow Haul as suggested will help some, but ultimately it's the much higher weight of a motorhome for each engine horsepower that makes them accelerate and climb slowly compared to cars and SUVs. If that's what seems like engine is struggling, it's just normal part of driving a large and heavy motorhome.
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08-31-2017, 12:23 PM
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#13
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Senior Member
Brand: Thor Motor Coach
Model: 37GT
State: Florida
Posts: 809
THOR #5246
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Going across country this summer and up into Canada we did a "few" grades. When I start my engine the tow/haul button gets activated. There were a few times when we were on perfectly flat ground for hours and hours that I would take it out.
As far as not letting a V-10 scream beyond 3,500 rpms. I suppose with a tiny motorhome and no load on certain grades that would be possible. With my Challenger only towing a 1600 pound load it is not possible. If climbing a 5 or 6% grade and the engine was forced to stay at 3,500 rpms or lower it would eventually start dropping rpms and speed and you would end up sitting in the driving lane as a parked vehicle!
If your V-10 needs to jump down into 3rd gear while going up a steep grade and the rpms are in the mid to high 4000 range so be it. Being in a "big hurry" has nothing to do with it. The reality is you have to try to maintain a speed of 40mph plus if possible to get up that grade. It really is no more complicated than that. You will have cars coming up behind you talking on their cell phones, putting on make-up, and who knows what else and they are traveling at 80 plus. Please do not lug your RV down and be in that driving lane going 25mph!
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Full Time in 2017 Newmar Ventana 4369
pulling a 24' enclosed (Mini Cooper/Harley/Kayak)
(traded 2014 Thor Challenger)
US Army 70-73 Retired LEO
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08-31-2017, 02:04 PM
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#14
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Senior Member
Brand: Thor Motor Coach
Model: Windsport 31S
State: Florida
Posts: 303
THOR #4443
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I have a 6 speed, and I understand the T/H mode but is there any advantage to manually shifting to 4 on the steering column.
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09-02-2017, 01:48 PM
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#15
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Senior Member
Brand: Thor Motor Coach
Model: Hurricane 35C
State: South Dakota
Posts: 1,132
THOR #3761
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Quote:
Originally Posted by penguin
I have a 6 speed, and I understand the T/H mode but is there any advantage to manually shifting to 4 on the steering column.
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Not that I can think of.
__________________
John
2016 Thor Hurricane 35C with pups Piper and Annabelle
2013 Ford Fiesta toad
FMCA - F457085
Blog - https://traversity.us
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09-02-2017, 02:19 PM
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#16
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Senior Member
Brand: Redwood
Model: 36FB
State: Arizona
Posts: 1,766
THOR #3610
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With your heavy mh towing the vehicle I'd use the tow/haul always, that's what it's designed to do.
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Fulltimed 10+ years
Sold '13 Thor Redwood 36 FB
Traded '13 GMC Denali DRW D/A
Replacement undetermined
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09-02-2017, 02:21 PM
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#17
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Member
Brand: Thor Motor Coach
State: Arizona
Posts: 85
THOR #6671
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This forum and all of you experienced RV'ers are simply fantastic. I especially appreciate the patient way you explain things to folks like us who are new at the game. Thank you for helping expand my knowledge base.
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