A nice downgrade example

I'm going to say the following:

What gear you come off of a mountain grade, especially like Eisenhower, which hits 8% for the first quarter mile and levels off to 6% for the remaining 8 miles of the pass, is going to vary on every single truck out there. There are numerous factors which influence how fast you can come off of a mountain. How heavily you're loaded, how strong your jakes are, how good your service brakes are, as well as weather conditions.

If my truck has a weak jake brake on it, I'm going to come crawling off the mountain at a significantly slower speed so that not only the mechanical resistance on the driveline helps keep my speed down, but, it allows me to use my service brakes more so, as well. The slower I'm going, the less I will heat my brakes up slowing down on a grade.

By the same token, I was coming off of Vail Pass awhile back in an '07 Peterbilt with an ACERT Cat under the hood. What an amazing jake compared to a 6NZ in my book. With a 6NZ I'd hit the hill 10mph under the truck speed limit on Vail (I'd be going 35mph). With that ACERT I was cruising down the hill at 45mph (maximum speed for trucks on the downgrades). The engine would wrap up into the higher RPMs and just hold the truck. I could count on one hand how many times I had to touch my brakes on that pass.

Gearing plays another important factor. The faster the gearing is in the truck, the lower the gear you're going to need to be in to come off of the mountain.

At the end of the day, you come off the mountain in a safe gear and a safe speed. This varies for every single truck, driver, and grade out there. It's the old phrase, "You can come off a mountain too slow as many times as you want, you only come off a mountain too fast once."

At the end of the day, when you have your first experiences running into the mountains, you pick a speed where you don't get spooked coming down that hill. If that's 15mph, you don't let a #### person tell you to go faster than that. They don't know your load, they don't know your driving skill, and they don't know your truck. Just because I come up behind you at 45mph off of a hill doesn't mean you truck can handle the same.

 

drivers with annoying loud jakes that run them when they dont need them makes up these laws
no one just says lets have a law before someone was abusing the privelege
why would anyone have the jake on in the TS other then cause he thinks he is cool

 

... um.... cuz I forgot!?

That's my story and I'm stickin' to it....

 

Because, if I don't prove to you how much larger my junk is than yours, well, then its just been a wasted day!

 

i like the sound of loud jakes but i much prefer trucks with super quiet jakes. iv drove some trucks that the jake brake is quieter than when your foot is in the throttle. i like that because i will just ignore every no jake brake signs and never turn the switch off.

 

Ahhh, the way I like it...Controlled descent. Lucky to have learned to truck in MT on Lookout, MacDonald, Lolo. Don't forget the 4 way flashers when going more than 10 mph slower than 4 wheeler speed. Watched plenty fly by me, then pass them at the bottom of the hill in a cloud of brake smoke. Many scoff at certain hills (Grapevine, Monteagle) but each has it's own treachery. After awhile, I enjoyed the challenge of riding the jake, and arriving at the end with nice, cool, unused service brakes.

 

Oh Mr. Diesel, forgive me, for I have Jake Braked. Adjusted trailer brakes & Generally don't want to die. Trucks are slow for a reason. 1000 times off a mountain too slow, no problem. One time too fast, dead trucker. Do the Math.

 

In 1984 my brother was northbound over the Grapevine with a load of rebar on a flatbed, wasn't paying attention and didn't start the down grade with a low enough gear. By the time he hit bottom the speedometer was already pegged at 90 mph. He elected to not use the suicide ramps and road it down all the way to the flat straightaway. It took over two miles to get his rig stopped. Had to shake the fecal tissue out of his drawers.

By the way, has anyone here actually used a suicide ramp? The thought of taking one of those at speed isn't one that would be high on any bucket list of mine...

 

That's fine when you're on a single lane but one of my pet peeves is people that run their 4 ways in the right lane when there's more than one lane in that direction. I was about to pass a guy that had his 4 ways on in the right lane, just as I was about to go by he put on his left signal and started to change lanes. My peripheral vision didn't pick up the the change from 4 way to left signal and the other driver didn't mirror check before starting his lane change. Fortunately, I always watch the distance between the steer tire and dividing line of vehicles I'm passing so I can see any change that might indicate that the vehicle is moving over and was able to hammer the brakes & back off before getting sideswiped. I had a similar situation happen following a farm tractor hauling hay bales. He had his 4 ways on, it was clear to pass so I pulled out and, again, he went from 4 ways to left signal to turn down a side road and almost took me out because once I was maybe 20 or 30 feet from the back of his load, the centre bales obscured the right flasher and I didn't notice the change from 4 way to left signal. BTW, advice often given on this forum regarding gear selection is "descend in the same (or x# slower) gears you went up the hill in. Pretty useless advice IMO because A-it assumes that you've climbed the hill before and often you haven't, and B-it assumes that you remember which gear you used if you had.