Going down steep grades with a Class C

The Logans wrote:
If you have a 6 speed tranny, just set the cruise control, and let the computer do it's job. Since we got the 6 speed, we haven't had to use tow haul.

The above is a true description of what happens under certain conditions ... but needs to be clearly and fully understood. BTW, the same description also applies to the earlier 5-speed computer controlled Ford TorqShift Tow/Haul E350 and E450 transmissions introduced starting with the 2005 Ford E350 and E450 chassis model years.

With the cruize control engaged - whether having the Tow/Haul mode turned on or not - the computer will control the transmission SO AS TO ALSO maintain your set speed even when going down a grade. The transmission will be automatically down-shifted by the computer as necessary to keep the E350 or E450 from not going any faster (if possible - using of course only engine braking) than the speed you set for the cruise control WITHOUT YOU TOUCHING THE BRAKE PEDAL. I'm not sure that way of using Ford's 5-speed and 6-speed TorqShift transmissions is known about by all owners.

HOWEVER, if you want to use the cruise control this way to automatically try to control downhill speeds ... you better be happy with going down a grade at the same set speed you had set before arriving at the downhill grade. This usually feels "scary" to me, so no later than at the top of a grade when in cruise control, I usually turn off the cruise control, make sure I'm in Tow/Haul mode, and then use the method of tapping the brake pedal so that Tow/Haul mode downshifts with each toe-tap until I feel that the downhill speed is safe ... which is usually slower than what I had the cruise control set to when approaching the grade.

So - you can get Ford's TorqShift transmissions to downshift for you on downgrades without you having to touch the shift lever by:

A) Using the Tow/Haul mode - with the cruise control not being turned on - when going down a grade so the computer drops a gear for you automatically each time you tap the brake pedal. BTW, with both the cruise control and Tow/Haul being in use ... and if you don't feel comfortable with the downhill speed that the cruise control is maintaining for you - just tap the brake to disengage the cruise control and then do more brake taps as needed to get the Tow/Haul mode to continue downshifting more for you.

OR

B) Keeping a set speed in the cruise control and the cruise control turned on so that the computer automatically uses transmission down-shifts to keep your speed going down the grade from not exceeding what you set for the cruise control.

To emphasize ... cruise control can be used whether having the Tow/Haul mode turned ON or turned OFF.

I hope the above is not too confusing. The 5-speed and 6-speed TorqShift transmissions are very flexible, but you must understand what they do in order to use their capabilities for the best safety and braking efficiency on downgrades. It took me a couple of years to fully grasp when and how to take advantage of all of these transmission operating modes - regardless of instructions in the Operator's Manual.

(Another confusing factor is that the earlier "5-speed" TorqShift transmission actually has 6 ratios in it. The computer assigns one or the other of a couple of these ratios to one of the five "speeds", depending upon outside air temperature.)

+4 Tow/Haul

Many (most) Class C's are on a Ford Chassis which comes with tow/haul mode. Tap the brakes going downhill and the transmission automatically downshifts.

Piece of cake. Try it. You will never have to touch your brakes.

The Logans wrote:
If you have a 6 speed tranny, just set the cruise control, and let the computer do it's job. Since we got the 6 speed, we haven't had to use tow haul.

The six speed trans in no way eliminates the need to use Tow Haul. By not using it you are generating higher transmission temps that will surely shorten its life. Adding a Scan Gauge or other display to show your trans fluid temps will quickly convince you. Read your owners manual, that TH button is there for a very good reason.

:C

I agree with most, use your transmission and pump the brakes when needed. When I first got our RV I over used the brakes on a long, steep and windy grade. When your brakes are on overheated and on the verge of failing in a 14000# vehicle it is terrifying. I'd gladly pay fir a replacement tranny then experience that again.

If you have a 6 speed tranny, just set the cruise control, and let the computer do it's job. Since we got the 6 speed, we haven't had to use tow haul.

It has been mentioned a couple of times and needs to said again... USE your Tow Haul! It is there for a number of very good reasons. On a long {10 - 12 miles and yes we have lots of them out here in the southwest}, 6 to 8 per cent grades be sure to engage the TH. I usually get to the bottom of the grade without touching the brake pedal and haven't burned a drop of fuel all the way to the bottom. You coach will benefit just as much from using TH going up as well but going down is the topic of the moment.

Most Class C's and certainly any C over 27' and/or towing should be in TH all of the time. Your coach will be more efficient and safer to drive. Using TH reduces your trans fluid temperatures which certainly will prolong the life of your transmission. The proper use of TH is spelled out in the owners manual but then real men don't read them.... right?

:B

fourthclassC wrote:
More important to avoid brake fade and fire from overheating brakes then wearing them out. I believe we should be using lower gear on big hills. My wife hates it because the transmission whines and thinks it is hurting it. Brake fade and wheel fire is much worse... I've seen it happen.

If my wife was like that I'd keep her busy making coffee and sandwiches :) Seriously, in addition to all the other problems mentioned from riding the brakes, the heat also warps the rotors. I learned that the hard way, and now I downshift and take my time.

CharlesinGA wrote:
Charles

This sounds right from what happens when I drive mine. At least that is what the face prints show on the windshield from the passenger and me when I do this and the thing slows down like I dropped anchor. Only issue I have is getting it to up shift again as it drags along, I started to take off tow /hail to get it back. I was able to just about stop my unit on a steep hill by doing this, freaky till I figured it out!

My understanding of the tow/haul mode on the Fords is that with it set to t/h and you decelerate the lockup clutch in the torque converter locks up completely, so it acts/feels like a stick shift, and when you tap the brake pedal, it downshifts one gear and on the six speed, it downshifts a second time if you again tap the brakes, but the converter stays locked up the entire time, so very little heat/wear is generated during all of this.

I went down a 10% grade the other day in my View (sprinter chassis) and I slowed while on the flat before the downgrade and downshifted into 4th and rather quickly into 3rd, and still had to use some brakes (it was a fairly short downgrade, but enough that there is a runaway ramp at the bottom of the 10% where is transitions to a 7% which ends in a traffic light).

Charles

one thing to say, do as the truckers do and they use the engine to slow down the trucks on a down grade. they will burn up brakes faster than you can spit if they didn't. school bus drivers are trained to use two gears lower going down a hill than going up. this should answer your question