Driving DOWN steep grades...

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Oscar Mike

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I am not sure where to post this.

I am very new to RVing...my total mileage behind the wheel of my Fleetwood Bounder 33U (V10 Ford) is under 500 miles, mostly back and forth to the dealer over the last four months getting warranty work done. As of late I have been bothered by the prospect of driving down 6%+ grades that are somewhat common out west. The thought of getting up the grade doesn't bother me too much, pull into the right lane and climb the grade...but what happens when we get to the down side... How should I approach the grade? Once I am committed to the downhill grade, what then.

I am overly worried...as usual, but it would be great to hear from veterans of the road on how you handle steep downhill grades in a 34', V10 with Tow/Haul function.

 
I have driven all over the west in a 32 foot gasser and I can't even think about what it is like to drive down 6% grades. It is not an issue at all. 6% really isn't that steep anyway. I wouldn't waste my time worrying about it if I were you.
 
SeilerBird is correct.  You're worrying unnecessarily.  A common practice is to go down the grade in the same gear you used to climb the grade.  Our western mountains aren't nearly as scary as people make them out to be.  Just be cautious and you'll be fine.

Margi

 
When you go over the crest of the hill you should already be slowed down to the speed at which you want to descend - or even a bit less so as to allow for some increase on the downside.  It is wise to shift to a lower gear too, to let the engine do more of the braking.  A rule of thumb is to descent thehill in the same gear you went up, but that is not very visible with an automatic transmission. You probably climbed in 4th or 5th gear if a 6-speed automatic, or 2nd or 3rd gear if a 4-speed.

You really don't want to "ride" the brake pedal all the way down a long grade - the brakes could conceivable overheat. If you need to use a lot of braking, the recommended "best practice" is to brake firmly for several seconds and then ease off to allow cooling.

If you follow these basic driving skill practices, you won't have any problems at all.
 
It is those basic driving skills that I am learning all over again. When I first purchased our Bounder I wasn't greatly concerned about driving the coach, but now after a few hundred miles I have a new appreciation for commercial truck/bus drivers. There is more to know in driving a wide, tall, and long motor home compared to driving my F550 with my Lance 1120 strapped to the back.

I've practiced in the local high school's parking lot, with parking, turning radius', backing, and so forth, but there is nothing to prepare me for the first time I will encounter a rather steep downhill grade, it is good to know at least the basics of the maneuver before I have lives in my hands.
 
Being as you are new to driving big stuff, I'll add this. The signs that warn drivers about curves ahead and reduced speed, they are for you. Highway ramps that say 35mph, cars are exiting at 60mph. Maybe there is a reverse camber on the bend? That won't affect a car like trucks, busses and rv's.
 
I have a 2008 F250 diesel and have driven 6% and greater hills up and down. The tow haul feature on my truck makes that effortless. In fact, with the cruise control on and the tow/haul working, it felt like I had Jake brakes on some of the monster hills.
Should be no problem for you.

Bob
 
driftless shifter said:
Being as you are new to driving big stuff, I'll add this. The signs that warn drivers about curves ahead and reduced speed, they are for you. Highway ramps that say 35mph, cars are exiting at 60mph. Maybe there is a reverse camber on the bend? That won't affect a car like trucks, busses and rv's.

This is very good advice, thank you...
 
Gary RV Roamer said:
When you go over the crest of the hill you should already be slowed down to the speed at which you want to descend - or even a bit less so as to allow for some increase on the downside.  It is wise to shift to a lower gear too, to let the engine do more of the braking.  A rule of thumb is to descent thehill in the same gear you went up, but that is not very visible with an automatic transmission. You probably climbed in 4th or 5th gear if a 6-speed automatic, or 2nd or 3rd gear if a 4-speed.

You really don't want to "ride" the brake pedal all the way down a long grade - the brakes could conceivable overheat. If you need to use a lot of braking, the recommended "best practice" is to brake firmly for several seconds and then ease off to allow cooling.

If you follow these basic driving skill practices, you won't have any problems at all.

If I understand you correctly, it is advisable to manually shift into a lower gear when climbing a hill instead of allowing auto shifting, then being in a,lower gear at the crest of the hill would be my dictate for speed on the downhill side. I am assuming that one would keep their RPMs at around 2,000 going up hill. So if I am able to make it up a 6% grade at 45 mph, my planned 6% downhill speed would be at 45 mph (of course taking road, terrain, and traffic conditions into account).

I apologize in advance for the dumb questions...but Inquiring Minds Need to Know... :)
 
Oscar Mike said:
If I understand you correctly, it is advisable to manually shift into a lower gear when climbing a hill instead of allowing auto shifting, then being in a,lower gear at the crest of the hill would be my dictate for speed on the downhill side. I am assuming that one would keep their RPMs at around 2,000 going up hill. So if I am able to make it up a 6% grade at 45 mph, my planned 6% downhill speed would be at 45 mph (of course taking road, terrain, and traffic conditions into account).

I apologize in advance for the dumb questions...but Inquiring Minds Need to Know... :)
There are no dumb questions. If you don't know the answer then it is an intelligent question.

I never bother to downshift either going down or up a grade unless it is a lot steeper than 6%. I see no point in worrying about RPMs.
 
Your tip off that it's going to be a steep grade that you should pay attention to, is the warning signs for trucks. If the sign says "steep grade ahead" it means the highway folks are trying to warn folks to pay attention. If you have a small rig, and/or don't mind paying more for brake work than you need to, then by all means fly on down the hill and ride the brakes. If you want to minimize the chance of not being able to stop at the bottom, cost of brake work, and nervous riders, then slow down at the top of the hill and manually shift down to the gear it would take to climb the hill.

The hard part is that each side of the hill may have a different grade, so you need to gain experience to be able to tell which gear it would take. You can always go up a gear if you find that the one you selected is too low. Once you have 20,000 miles under your belt it will be automatic to read the road and know how you want to descend. Until then, be conservative and take care of your equipment.

Ken
 
I let the transmission choose the gear going up the grade. If it is dropping in and out of overdrive I do shift it out of overdrive.
Going down a grade the idea is to use the brakes as little as possible and down shift to a gear that holds you at the max speed you want. If the speed creeps up then stab the brakes to get back down to a comfortable speed.
 

Your RPM will be double or more going up.  The engine is designed for this high RPM to produce the torque to climb.  The engine will scream and you may feel uncomfortable but you are not hurting the engine.  Notice there is no red line on the speed meter.

Jennifer
 
Bobandpamlemay said:
I have a 2008 F250 diesel and have driven 6% and greater hills up and down. The tow haul feature on my truck makes that effortless. In fact, with the cruise control on and the tow/haul working, it felt like I had Jake brakes on some of the monster hills.
Should be no problem for you.

Bob

That's been my experience with my F-250 pulling our 5th wheel....even in the 9%-12% grades.  Keeps me at that speed all the way to the bottom....no brakes needed.
 
Going up hill isn't much of an issue unless the transmission starts "hunting" (e.g. shifting back and forth a lot) or if you drop in speed so much that you feel like you're barely moving.  In either case you should downshift manually to get the transmission into a better place.  We had a vacuum gauge in our class C gas motorhomes and used it as a guideline for changing gears.

You've received good advice about going downhill.  If you reach the top in fourth gear, then start down in fourth gear.  If you're going too slow you can always shift to fifth or if you're going too fast you can always brake some and downshift to third.  The idea is to use the gearing instead of your service brakes to "save" them in case of serious need for slowing.  If you pick up speed, give the brake pedal a good hard push to bring down your speed to where you want it.  Every vehicle has a different point at which the transmission will shift upward or downward.  Ours happens to be at 35, 45, 55, 65 so on downhills we begin braking some about 33, 43, 53, and 63 so it won't suddenly increase in speed when it reaches that magical "5" in speed.

Also, as others mentioned, use the signs for truckers as a guideline.  Some of our western hills have a 17 mile downgrade but it's a relatively straight road so it's not a big issue.  You just don't want your speed to creep up on you so that you have to ride your brakes.  You'll do just fine following the comments here.

Joel - You found a good picture of Oh My God Hill!  :D

ArdraF
 
Let's say that you are on a certain long grade and want to maintain 50MPH (as example).... let the coach get to 55 tops, then brake to 45. When you let off the brake @ 45, the speed should just sneak back up to 55. If you are forced to brake again is say... under 15-20 seconds..... slow her down and grab the next lower gear until she is able to maintain a comfortable speed without having to touch the accelerator and just lightly brake. Once she slows on her own, grab the next higher gear and try it again to maintain your desired speed.

BTW....... when you let off the brakes.... take your foot completely off the brake pedal. It is important that the brake pads are not contacting the rotors at all so that they have that time to cool.

Practice this on the 1st couple grades until you feel comfortable. The last thing that you want to do is constantly having to brake every 10 seconds. If you are on a long grade, you may boil the brake fluid and/or experience brake fade.

You are very wise to ask these questions now rather than when you are on the way down a grade, trying to get an internet connection..... :eek:

The big thing is to stay within "YOUR" comfort zone. For the most part, your rig should handle the posted speed limit just fine.
 
When you get done with the 10% grades you can graduate to this one. We basically let the jake brake do the work, with a few taps on the brakes now and then. This one was for 8 miles and then it leveled off to only 12% for the next 10 miles!!  ;D
 

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