Anyone had to use a runaway truck ramp?

I go down some long steep grades with 10 pounds or less on them every day I run, and you don't ever see any smoke or smell them, use 20 or more for long and they do get hot. I will use that much to go to a lower gear when the grade changes, but just long enough to drop my speed down enough to shift.

 

There are speed limit signs on big down grades for a reason.
Jake's do not work well at 2800 rpm.

Do not drive on Teton Pass if you are ove 30,000 lbs gross. It's illegal!
You have been warned.

 

Ive had only one truck where it did from 3000 on down. But it's a one off engine and wide open if you were able to manually pull the lockout knob at speed to bypass the 2400 rpm redline and gain another 20 or so mph with it. The problem is you would have had to unlock it fast if you needed to stop, because you wont. lol.

Jakes work good in my experience up to about 1900, 2100 or so in 2300 engines. 1800 or so in 2150 engines and so on. Anything more its just noise and it will add speed on the way down.

 

Over here on the east coast I don't think I can recall ever seeing a truck on a runaway ramp. They just like to leave them at the bottom of the hill on fire.

 

If my truck ever sees 2800 rpms I will already be on the running board bailing out. lol
I do not know if you have ever been in Mt Ranier national park, but it is illegal for any truck to be on that road, and for good reason. However that does not matter you are doing road construction. Twice we worked in their with the asphalt recycle train, and I had to pull the train every morning and evening at up to 245,000 gross depending on how full the oil tanker was, and the rest of the day pull two tankers one lime and one oil, domed out when we unloaded the trucks at 160,000 or so. steep grades and 10 and 20 mph switchbacks the norm.

 

I have one of those 3000 rpm engines, it is a 3208 kitten, not much more horsepower than my pickup probably. lol

 

Keep an eye on those main bearings at crankshaft. If they ever go out of alignment or wear wrong at those high values you don't have a engine anymore. At least that was what I was told. There isnt any way to keep a eye on something like that I don't think if you are not able to pull the pan.

You are right, pickups probably put out a greater value in terms of power and torque than some of those early engines now.

 

If I can get down a hill in an auto anyone can. Ideal conditions I'll start the grade at like 50MPH or so and give the jake maybe 2 clicks and see how it handles. More clicks or less depending on how it reacts... maybe a few pumps service brake if it starts to get away from me.

Not saying that's the way you should do it, but it's served me well so far.

Less than ideal conditions I'd probably start the grade slower and use service brake more, engine less. I learned in a SDakota blizzard too much engine brake and not enough service brake can have undesirable results. Fortunately I wasn't going fast at all and recovered easily.

I just try to feel through it and respect conditions if they exist. The auto shifting hasn't given me any problems so far.. only my own doings

 

i can go down most interstate mountains without touching the brakes but 1 or 2 times. i always get into right gear and jake on.