Check your Trailer Controller and Increase Gain for Steep Downhill Grades

[jd1923]

We are home safe now though I ran into quite a learning situation on our final stretch home. We spent the night at Rockhound SP near Deming NM and the next night was Roper Lake SP near Safford AZ.

The normal route would be to take I-10 to US HWY 191 for a 2 1/2 hour drive. We've driven that route as well as US HWY 70 from Lordsburg to Safford. We really wanted to see Silver City and take a scenic route (see map) adding another hour to the drive. 

Heading NM on US HWY 180 out of Silver City we turned left on US HWY 78. Perhaps I should have heeded the warning at the turn, "Not Recommended for Truckers, Steep Downhill Grades." We had traveled up over 9000 ft in the White Mountains of AZ and all through Lincoln Co NM climbing and descending 1000s of feet in altitude without concern.

What a beautiful drive and HWY 78 was not one of those cliffside roads, not scary with safe shoulders. There was a section after entering AZ that first climbed much higher and then it must have dropped 2500 FT in just a few miles, OMG! Zoom in to see the road (second pic). Much of the incline is behind the mountain and cannot even be seen and we are miles away when we stopped.

After we got more than halfway down, I felt the upgrade HD brakes on our Dodge Ram start to fail. I have felt this before, so I knew what it was, from driving the heavy old cars of the 50s that would overheat and fade. The speed limit was marked at 30 MPH with many curve warnings at 20 MPH. I never exceeded 25 MPH regardless my brakes overheated. I have an infrared heat measurement gun. Parts of the discs were at 360F and the caliper holder on the right side was the hottest just over 400F. I was thinking why? We sat there for 30 minutes until all temp reading were down to 160F. (See 3rd pic for side view where we stopped.)

I realized the truck was breaking for the trailer that the trailer brakes were not engaging hard enough for the extremely steep grade. The gain was fine for driving around town but should be increased for highway speeds and what I've learned now is that it should be increased more for declining steep grades.

Thought I should write this up, so others do not get into a similar or worse situation. Maybe there are better controllers? Mine has a digital readout, numbers getting larger as the brakes are depressed harder. As they were the numbers only got up to 20 or so. After I increased the gain, the numbers were reading well over 40. I have never driven down such a mountain road with all the steep up and downs we have in the Rockies!

[DavePhelps]

Good post JD.

I hope a lot of folks read this. I learned early on that the brake controller is not a "set and forget" device.
I am always tweaking mine depending on road conditions, speed and especially GRADE!! At the start of a long steep descent, I put the gain way up. I can tell now when the TV and trailer are in sync with each other. Good thing you have an HD truck and glad you are safe. Brake failure on some of the steep grades we have out west is not an option!

Does your Ram Cummins not have an exhaust brake? Not a diesel owner but thought that was one of their great benefits.

Cheers,

Dave

[Mike and Carol]

 

12 minutes ago, DavePhelps said:

Does your Ram Cummins not have an exhaust brake? Not a diesel owner but thought that was one of their great benefits.

I check my gain on a regular basis, a habit I got in to with the smaller half ton trucks I towed my Oliver with.  The last 4 years with our 2500, the big 6.7L Cummins does most of the braking.  

[SeaDawg]

I suspect you were, but we're you downshifting, going down the mountain?

 

[Patriot]

On our recent trip Western loop traveling over the 10% grade on Teton Pass from Victor Idaho to Jackson Hole Wy 5 different times we let our 6.7 V8 diesel engine brake work its magic. I am happy to report it worked flawlessly and I rarely if ever had to use our truck or trailer brakes. I will give Ford credit, they nailed it on their diesel engine braking tech with the new 10 speed transmission.  

(Edit - We would not have been comfortable traversing the Teton Pass with any other TV).

This thread is a good reminder to check your braking systems for sure.

Glad you made home safely @jd1923. 

Edited Sunday at 12:41 PM by Patriot

[jd1923]

3 hours ago, SeaDawg said:

I suspect you were, but we're you downshifting, going down the mountain?

Not much downshifting on an older 4-speed automatic where 4th is overdrive. The Dodge has an OD OFF button on the shifter which I use always on uphill grades 55 MPH or less and did so on this steep downhill. And yes, had it in 2nd gear some.

1 hour ago, Patriot said:

diesel engine brake work its magic

Until this stretch of road, I wondered if I truly needed one. @DavePhelps the older diesel pickup trucks did not have this feature, mine being a 2001. Only Class-As and commercial trucks had them back in the day. I believe Ford/GM/Dodge added them to diesel pickups over the last 10-15 years.

I've had this on my upgrade list for a while: C44075 Direct Mount 4 inch PRXB Exhaust Brake Kit w Max Flow Design for 1998.5 -2002 Cummins 5.9L (pacbrake.com)

Please keep in mind the point of the warning here. Of course, make sure your braking systems are in good maintenance but check your brake controller settings. I had not realized this setting should be adjusted as Dave and Mike had suggested/written above. Thank you.

I cannot afford a late model Super Duty 350 Diesel though my Ram 2500 is a lot more truck than many Oliver Owners towing with 1500 series gasoline engine trucks. Trailer brakes are very important even with an engine brake. @Patriot owns a truck that can tow a 35' fifth-wheel or pull a triple-axle toy-hauler loaded with two full-dress Harleys! Would love to have one, but that's not in the cards for us. I had also upgraded the front brakes on my truck to larger 3rd Gen brakes designed for a heavier pickup with greater GVWR.

Otherwise, do not travel this kind of road. The roadside warning was intended to 18-wheelers though next time instead of going for it, facing my fears, I should pick another road. Wow though what a drive, what beauty! I realized the brake fade soon enough, stopped, measured temps, chilled for 30 minutes, walked the dog. Increased the gain much higher and continued winding slowly down the mountain, 20 MPH average through this section of road.

BTW, there is a stretch of road, in an area called "Top of the World" on US HWY 60 between Miami and Superior AZ that is one of the most breathtaking drives we've ever done including many in UT and CO. That was our next day on our way home. 

Always glad to be home and what a great trip we had taking 3 1/2 weeks just to roam what is otherwise a 2-day drive each way!

Edited Sunday at 04:57 AM by jd1923

[Ronbrink]

Both of my GM TVs (Chevy Silverado 1500 and GMC Savana 2500) are gassers equipped with the Tow/Haul feature; selects a lower gear for better engine braking effect and optimizes transmission shifting. They also have Manual mode, especially beneficial when going uphill or down a steep slope. I always engage Tow/Haul when trailering the Oliver and have used the Manual mode on occasion with the Silverado when towing in mountainous areas, but nothing too extreme; works great in lessening actual use of the vehicle’s brakes to ‘slow the go’! Something I noticed different with the Savana in the hills encountered on our most recent travel into Texas Hill Country, was the very apparent and effective downshifting of its 6-speed transmission when slowing for a stop, as well as down grade at speed. Could be that it is basically a commercial vehicle designed for carrying and handling heavy loads under adverse conditions. The hefty front and rear disc brakes, 12.8” and 13” rotors respectively, was another bonus; I rarely had to manually engage the brake controller, especially for quick stops at sudden traffic light changes. Because my wife has ‘extreme anxiety’ with thought of “those cliffside roads” that  @jd1923 mentioned, I may never experience his described encounter; but then our GPS Navigation has taken us down many a path of uncertainty, don’t ya know! 

Edited yesterday at 11:12 AM by Ronbrink

[jd1923]

3 hours ago, Ronbrink said:

our most recent travel into Texas Hill Country

We didn't have to worry much in the rolling hills of Central Texas, elevation 1200-1800 FT max. The descent on AZ HWY 78 was over 3000 FT in about 15 miles. What caught me by surprise is that we had climbed to 9300 FT and descended the White Mountains of AZ and over 8000 in Lincoln Co NM, no issues. This drop in elevation in such a short length of road was extreme.

Check out the sign in my first picture. Ever see a grade warning this steep? Twice we have wanted to visit Tonto Natural Bridge near Payson AZ. Both times I was towing. We did not realize the road to this park was so steep. This sign was at the exit of a turn-around area they had for us towing travel trailers! We passed on this visit not having time to disconnect and honestly, I did not want to attempt this descent even without the Oliver!

Interstates and US highways have 6-8% grade max when speeds are >55 MPH. They did not have grade signs on AZ HWY 78 though I'm certain it was at least 10% in some stretches. Maybe Tonto Natural Bridge another time. It's only 2 hours from home.

[jd1923]

11 hours ago, jd1923 said:

BTW, there is a stretch of road, in an area called "Top of the World" on US HWY 60 between Miami and Superior AZ that is one of the most breathtaking drives we've ever done including many in UT and CO. That was our next day on our way home. 

Pictures from "Top of the World." The first picture does not do it justice. This drop in person looked like if you were driving at 50 MPH right on the edge of the Grand Canyon, OMG my heart was pumping! Final pic is the truck runaway just prior to a tunnel through the mountain. US HWY 60 descending to Superior Arizona.

[Zodd]

This is one reason I have loved RV Tripwizard for trip planning as it will show you not only the elevation gain/loss but also the percent grade on the roads. I have often wonder what my “I’ll pass” limit would be. Once it hits double digits I start questioning. Since I am out west this is one of the reasons I went with a 3/4 ton to ensure more stability through all these mountains. 

Edited Sunday at 04:54 PM by Zodd
Grammer

[John Dorrer]

4 hours ago, jd1923 said:

Pictures from "Top of the World." The first picture does not do it justice. This drop in person looked like if you were driving at 50 MPH right on the edge of the Grand Canyon, OMG my heart was pumping! Final pic is the truck runaway just prior to a tunnel through the mountain. US HWY 60 descending to Superior Arizona.

Sweet

[Rolind]

As an aside, I think on a super duty, if adaptive cruise and engine brake are both engaged, the adaptive cruise will apply TV brakes in addition to engine braking.  I usually don’t use adaptive cruise on big declines for this reason. I want to have a better idea of how much the TV brakes are applied. Any thoughts?

[Zodd]

This is one reason when towing I like to have my trailer info showing on my super duty display. It will show when and how much trailer breaking is being applied. However, going down hill I normally don’t have cruise on as I like to stay engaged with what my speed is. Downshift to a level that holds my speed versus letting cruise manage it. 

[Ronbrink]

On 11/3/2024 at 10:02 AM, jd1923 said:

Final pic is the truck runaway just prior to a tunnel through the mountain.

I drove an 18-wheeler for six months helping a friend with his transport business, some of which while hauling grain up through Palo Duro Canyon in north Texas and into Oklahoma. Saw many a truck runaway ramp and quickly appreciated their purpose. These ‘big-rigs’ have air brakes which can fail if applied too often on extensive down hill slopes; a situation wherein air demand exceeds the capability of the onboard compressed air supply or even a malfunction to the air system (compressor, air tank, air lines) itself. These off ramp structures are comprised of a deep bed of sand or gravel, an effective method of safely slowing heavy vehicles like trucks and even buses to a stop. The sign displayed in @jd1923’s pic reads ‘RUNAWAY VEHICLES ONLY’, guess that includes an Oliver TV, as well. Safe travels!

Edited 21 hours ago by Ronbrink

[Boudicca908]

On 11/3/2024 at 7:24 AM, Ronbrink said:

Both of my GM TVs (Chevy Silverado 1500 and GMC Savana 2500) are gassers equipped with the Tow/Haul feature; selects a lower gear for better engine braking effect and optimizes transmission shifting. They also have Manual mode

This summer I experienced my GM Silverado's engine braking -- it was the first time that I recognized what it was doing, and it is fantastic.

I'm glad you had the tools to measure temperature and the knowledge to recognize what was happening, and what to do @jd1923