Freightliner auto-shift is your friend. Set the speed, move the retarder switch on the handle one notch, and watch your speed. The auto-shift will allow you to move to the cruise control-set speed and the Jakes will kick in automatically as needed. I have driven the newer Freightliner on hills (not the Rockies or such) and this is what happens.
So if you have a downgrade speed of 40mph, set that and just make sure you don't overspeed anyway.
In my Freightliner 12 speed Auto, the descent mode automatically kicks in at 5-7 mph past my cruise set speed, without touching the Jake switch. So in the Rockies or any other similar grades, if I'm tooling along with my cruise at 60, descent mode will kick in at 65 or so, holding me at that speed. If I'm uncomfortable at that speed, I just lower my cruise setting to 55 and it'll hold me at 60, or 50 will hold me at 55, etc. It may not be this way with every truck, but it is with mine.
A couple things to note:
1- If the grade is steep enough and you have a heavy load, your inertia will surpass your Jake's ability to slow you enough. You will have to apply your service brakes. This doesn't often happen.
2- If/when you apply your service brakes, your cruise will shut off as well as your descent mode. It'll be up to you to use your Jakes / brakes to slow yourself.
Don't let it worry you too much. The Jakes on these Freightliners are pretty bada$$. You have three settings, and the third setting will slow you on just about any grade you encounter. You'll figure it out. Just always always pay attention to your speed.
@PackRat "Set the speed, move the retarder switch on the handle one notch, and watch your speed." By retarder switch do you mean Jake Brake position 1?
I asked my trainer what speed to descend. He looked at me like I was an idiot and said "the speed limit of course". Is that right? We're loaded at 78k pounds. I thought the posted speed limit was for cars and that my top speed especially at my current weight would be way lower. Is my understanding way off?
I run the Rockies and other steep mountains frequently. A couple of things to add to the great advice already posted:
1) If the roads are or might be slippery, be careful using the jake brake. Do not use the cruise control, and do not just cancel it but turn it completely off. Do not use jake 3. Try to use only jake 1....use jake 2 with caution. The autoshift will upshift on you, well..automatically, of course, especially when the jake isn't on or is only in position 1, so you may also want to manually keep it in a lower gear. Typically 8 is great for the steep downgrades if really long and steep, then maybe 7. There are places where there is a special very low speed limit for trucks in some states....I recall seeing them in Califorinia, Colorado, and Pennsylvania. There is a manual mode button on the stalk that may or may not work - give it a try. Either way, use the stalk to downshift...just get the RPMs down to proper level and keep them there with the service brakes. If you have clear dry roads, then all jake positions are fine, just watch the RPMs.
2) Freightliner has a video on winter use of their systems - install the Freightliner app on your phone - there is a place to input the VIN of the truck and then you'll see a bunch of videos that are for you.
3) Watch your RPMs when manually gearing down. For the 2017 Cascadia that I drive, Freightliner says the max is 2400. Your company may specify a lower number - my company specifies 2200. You have to hold them down with the service brakes when necessary. Apply the brakes until you are 5mph lower than you want to max at, release and let it speed up if conditions permit, rinse and repeat as needed.
4) Your trainer should be good at demonstrating all this - or s/he should't be training. I pick up students in Salt Lake City, and these things are one of the first things we go through once on the road.
Happy Freightshaking!
Your advice on Winter Driving was great! Just picked up load in Alsip, IL destined to Seattle. My trainer says we're running a team load, he's putting in his 11hrs driving then I'll do 11. Looks like we're taking I90. Hard to make out what Google Maps satellite view shows. Googleing I90 tells me about Lookout Pass. Are there grades on this route I need to be prepared for. I trained on a 10 speed manual. Now I'm in a Freightliner Cascadia with a 12 speed automatic. What's the proper way to descend with an automatic transmission? There's supposed to be a descent mode on cruise control that can be used in dry weather but I can't figure out how to engage it. On manual setting I've read of 2 different ways to descend (1) subtract the grade from the number of gears, that's the gear you descend in. (2) Grade 6 or less use 5th gear, greater than 6, use 4th. Your advice is greatly appreciated. (Cue line from movie Fury "Best !&$ job I ever had!")
Your trainer should be good at demonstrating all this - or s/he should't be training.
Dave, I wholeheartedly agree with that statement, however in Villian's situation he has little or no choice. He cannot get hired by the large carriers, and he has got to stick it out with this company and figure this stuff out on his own. He has little option but to rely on us here for advice. Hopefully he can survive a few years and get some experience so that he can move on to bigger and better things at that point.
I'm also dining a Freightliner with an auto shift 12 speed.
To set the decent control. Take truck out of cruise! Either hit the brake or hit cancel so it is not actively in cruise. You CAN NOT set decent assist while cruise is active. Set the engine brake in any position, position 1 is just fine. Now after turning engine brake on, reset your cruise control. If you set your cruise control to 55 the truck will adjust the engine brake to hold you at or below 55. It will not use throttle in decent mode! It will only coast in gear while below your set speed or use engine brake to hold your set speed.
Once you are at bottom of hill just flip the engine break off and normal cruise control will kick back in. You can adjust your set speed from there.
If you turn on the engine break while cruise control is active it will automatically go to max engine break and just keep slowing you down with no concern for current speed.
If you leave it in normal cruise down the hill the truck will allow it to go 7-10 mph over your set speed before it starts to use braking. This can be dangerous as you may be now going to fast for the brake to slow you down.
I absolutely love the hill decent and use it very often to be sure I don't exceed speed limits downhill. Also if I see a sign for a 45 mph curve ahead on a downhill I'll set it to 40 or 45 to make sure I am ready for that curve. Then just flip the engine break off and readjust cruise speed when I'm near the bottom of the hill.
Operating While Intoxicated
This approach can work but it is not for winter/bad weather which I thought was at least part of what the OP was wondering about, and also it is not for all years/models of Freightshakers. I've seen this on some trucks, but I do not have the feature on my truck, for instance. It is really best to go to the Freightliner app, input VIN, and watch the videos that they will then supply. Also, if the truck came with services manual and cards, etc. intact, then read them. Finally, there should be a sticker below the dash that gives some info about the shift functions on the truck.
I'm also dining a Freightliner with an auto shift 12 speed.
To set the decent control. Take truck out of cruise! Either hit the brake or hit cancel so it is not actively in cruise. You CAN NOT set decent assist while cruise is active. Set the engine brake in any position, position 1 is just fine. Now after turning engine brake on, reset your cruise control. If you set your cruise control to 55 the truck will adjust the engine brake to hold you at or below 55. It will not use throttle in decent mode! It will only coast in gear while below your set speed or use engine brake to hold your set speed.
Once you are at bottom of hill just flip the engine break off and normal cruise control will kick back in. You can adjust your set speed from there.
If you turn on the engine break while cruise control is active it will automatically go to max engine break and just keep slowing you down with no concern for current speed.
If you leave it in normal cruise down the hill the truck will allow it to go 7-10 mph over your set speed before it starts to use braking. This can be dangerous as you may be now going to fast for the brake to slow you down.
I absolutely love the hill decent and use it very often to be sure I don't exceed speed limits downhill. Also if I see a sign for a 45 mph curve ahead on a downhill I'll set it to 40 or 45 to make sure I am ready for that curve. Then just flip the engine break off and readjust cruise speed when I'm near the bottom of the hill.
Operating While Intoxicated
Now I'm in a Freightliner Cascadia with a 12 speed automatic. What's the proper way to descend with an automatic transmission? There's supposed to be a descent mode on cruise control that can be used in dry weather but I can't figure out how to engage it.
He was asking about use in dry weather....
Was just answering his question. That's how you engage decent mode in my Freightliner. But I guess it's very possible it's different in different years or packages of Cacadia.
I asked my trainer what speed to descend. He looked at me like I was an idiot and said "the speed limit of course". Is that right? We're loaded at 78k pounds. I thought the posted speed limit was for cars and that my top speed especially at my current weight would be way lower. Is my understanding way off?
You're exactly right. Hopefully your trainer won't be trying to get you to drive faster than your own comfort level through the mountains. I don't think I'd rely on the cruise to control my speed down a mountain at that weight unless I knew the road pretty well. Remember also that Lookout Pass isn't the only steep grade between you and Seattle. I don't think it's even the worst. As you get comfortable with your machine you'll be ready for all of the mountains. You're doing fine.
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Your advice on Winter Driving was great! Just picked up load in Alsip, IL destined to Seattle. My trainer says we're running a team load, he's putting in his 11hrs driving then I'll do 11. Looks like we're taking I90. Hard to make out what Google Maps satellite view shows. Googleing I90 tells me about Lookout Pass. Are there grades on this route I need to be prepared for. I trained on a 10 speed manual. Now I'm in a Freightliner Cascadia with a 12 speed automatic. What's the proper way to descend with an automatic transmission? There's supposed to be a descent mode on cruise control that can be used in dry weather but I can't figure out how to engage it. On manual setting I've read of 2 different ways to descend (1) subtract the grade from the number of gears, that's the gear you descend in. (2) Grade 6 or less use 5th gear, greater than 6, use 4th. Your advice is greatly appreciated. (Cue line from movie Fury "Best !&$ job I ever had!")