Descending down a mountain

[zackyboy3rs]

1st timer hauling North Carolina mountains. Little nervous about the descent on the way back to flat land. I will be towing my parents TT which is 7500lbs total weight. Give me any tips or pointers. Tow/haul button on, gear down? Bend over & kiss my a$$ goodbye or what? Thanks

[Mr_Beebo]

I have the 2500 6.0 with the 6 speed tranny and 4.10 gear. I'll be thru the Smokies again in about 10 days and then over to Myrtle Beach. You have all the info you need in the above posts to explain how to handle the mountains. Your 3/4 ton has beefy 4 wheel disc brakes, a strong transmission and plenty of horses under the hood. A reminder that when you hit your brakes during a descent while in tow/haul mode, your transmission will also downshift to help reduce speed. If your a little nervous or white knuckled, it can cause you to jump in your seat the first time it happens. You have the right truck and after a bit of windshield time you will have the confidence as well.

[Nvr2loud]

bud121156 wrote:
I was more concerned about the engine turning ~4000 RPMs going up the mountain. I backed off, and kept the engine closer to 3000-3200 and was much more comfortable.

What engine do you have in your 1500?

I have the 5.3 in my 2011 Sierra and I try to keep it above 3000 RPM almost the entire time I tow. It produces peak HP at 5200 RPM and peak torque at 4000 RPM.

I find the transmission gets way too hot if the engine speed runs too low, and the fuel consumption goes way up when the engine speed runs too low.

[brulaz]

opnspaces wrote:

...
I've never driven a downhill like that with the 20mph turns but I can see how that would heat the brakes up. Were the truck brakes starting to act funny that prompted you to use the trailer brakes alone? Just wondering because it seems that if the trailer brakes will fade faster then the truck it would be a mistake to use them alone to also slow the truck.

Didn't notice fade on the truck brakes but could definitely smell them half way down the mountain. That's when I started separately applying the trailer brakes.

I knew the trailer brakes were capable. They just weren't doing their job. The trailer weight was about 6500# on two 5200# axles with four 12" brakes. I had just adjusted the brakes a few days before so they would lock up on emergency stops, normal temperatures, at level 8/10 on the built-in Ford brake controller. So I had set the controller to 7.5/10 initially. But as those drums heat up and expand, you need more volts to get the same braking effort. So I started increasing the volts, eventually to 9.5/10 with no lock-up, and manually applying the trailer brakes when I noticed the truck brakes stinking.

In the old days, with drum brakes on cars, you just pressed harder on the brake pedal as they heated up. With electric trailer brakes you gotta do that electrically and manually as they heat up.

But like I said, it would have been smarter to pull over and let them cool off.

[Monaco_Montclai]

in 18wheeler school, they say to apply the foot brake enough to keep the speed from building, the material in the pads, are desgined to take care of that much.just drag the brakes, ever so slite. works for me. now its all happy-camping

[cantfindusernam]

You will be fine.

[opnspaces]

brulaz wrote:
One more thing, if you're going down a hill with lots of sharp 20mph turns, that can be a lot harder on your brakes than a steeper, but straighter and faster descent like on the Interstates.

And the drum brakes will fade faster on your trailer than the disk brakes on your truck. The trailer brakes will need constant re-adjustment via your controller as they heat up. On the western descent with all the hair-pin turns down the pass in Great Smoky Mountains N.P., I kept increasing the voltage to my trailer brakes as they heated up so the trailer would keep doing its part. I also started manually operating them to give the truck brakes a break. That was all in 2nd gear. All the brakes were stinking hot by the time we got down. Probably should have pulled over to let them cool.

I've never driven a downhill like that with the 20mph turns but I can see how that would heat the brakes up. Were the truck brakes starting to act funny that prompted you to use the trailer brakes alone? Just wondering because it seems that if the trailer brakes will fade faster then the truck it would be a mistake to use them alone to also slow the truck.

[brulaz]

One more thing, if you're going down a hill with lots of sharp 20mph turns, that can be a lot harder on your brakes than a steeper, but straighter and faster descent like on the Interstates.

And the drum brakes will fade faster on your trailer than the disk brakes on your truck. The trailer brakes will need constant re-adjustment via your controller as they heat up. On the western descent with all the hair-pin turns down the pass in Great Smoky Mountains N.P., I kept increasing the voltage to my trailer brakes as they heated up so the trailer would keep doing its part. I also started manually operating them to give the truck brakes a break. That was all in 2nd gear. All the brakes were stinking hot by the time we got down. Probably should have pulled over to let them cool.

[Community Alumni]

sacmarata wrote:

proxim2020 wrote:

Passin Thru wrote:
BB is 6% for 5 miles, some interstates are 9%, but no more out west. Never saw anyone descend up a mountain!

All "interstates" must be AASHTO compliant and restricted to 6% grade. Waiver can be issue from the Federal Highway Administration for mountainous regions, but restricted to 7% with speeds under 60 mph. The Eisenhower system is designed to move military equipment across the country quickly and efficiently. When moving heavy or sensitive equipment, grades are important.

Are you a state highway official?

Nope, but I enjoy researching and reading about all kinds of things. You can check out "A Policy on Design Standards - Interstate System" for all of the standards that are applied to interstates. Also you can find copies of "The Green Book" online which show standards for road and highway design.

[W_E_BGood]

HERE is one source.

And another

[Terryallan]

sacmarata wrote:

proxim2020 wrote:

Passin Thru wrote:
BB is 6% for 5 miles, some interstates are 9%, but no more out west. Never saw anyone descend up a mountain!

All "interstates" must be AASHTO compliant and restricted to 6% grade. Waiver can be issue from the Federal Highway Administration for mountainous regions, but restricted to 7% with speeds under 60 mph. The Eisenhower system is designed to move military equipment across the country quickly and efficiently. When moving heavy or sensitive equipment, grades are important.

Are you a state highway official?

don't have to be. It's public knowledge. Your's for the reading.

[sacmarata]

BurbMan wrote:
Use your tow/haul button and watch the speed limit on the road. If you shift manually to 2 it will hold your speed to about 45 mph. Drop down to 1 and it will limit you to about 30, no matter how steep the hill is. but that engine is gonna rev! If no sharp curves, I would put it in 2 at the top and let it go. Tap the brakes as necessary. If you see signs for sharp curves, you can brake to 25 or so and drop into 1. Try to use the brakes as little as possible, and watch the trans temps as you descend the hill.

Good advice here.
The only other thing I can add is that if you aren't confident going into a situation, then you probably need more seat time with this rig before tackiling anything that makes you pucker. Experience pays dividends and talk is cheap.
It all says easy but does hard if you are new to the situation and in the moment.
Don't forget, you can manually control just the trailer brakes if needed.
Also, regardless of what others may tell you, there is an unsafe minimum speed on interstates. Don't get too carried away and creep down an interstate grade so slow that you are a hazard to others.

[sacmarata]

proxim2020 wrote:

Passin Thru wrote:
BB is 6% for 5 miles, some interstates are 9%, but no more out west. Never saw anyone descend up a mountain!

All "interstates" must be AASHTO compliant and restricted to 6% grade. Waiver can be issue from the Federal Highway Administration for mountainous regions, but restricted to 7% with speeds under 60 mph. The Eisenhower system is designed to move military equipment across the country quickly and efficiently. When moving heavy or sensitive equipment, grades are important.

Are you a state highway official?

[BurbMan]

Use your tow/haul button and watch the speed limit on the road. If you shift manually to 2 it will hold your speed to about 45 mph. Drop down to 1 and it will limit you to about 30, no matter how steep the hill is. but that engine is gonna rev! If no sharp curves, I would put it in 2 at the top and let it go. Tap the brakes as necessary. If you see signs for sharp curves, you can brake to 25 or so and drop into 1. Try to use the brakes as little as possible, and watch the trans temps as you descend the hill.

[zackyboy3rs]

Thanks to all of you.

[pf32450]

As others has stated gear down or use tow haul. You did not state which mountain you are going down but if it is I-40 out of Black Mountain about 6% for 5 miles levels out nicely at Old Fort. Good Luck and happy travels.