Descending Steep Downgrades In An Automatic

That's Cabbage Hill! There's a truck stop not far after that hill where you can get your "I survived Cabbage Hill" shirt lol.

The Autos hill decent is magical on that hill in dry weather. At the top of the hill engage the engine brake (position 1 is fine) and then set the cruise at the speed you want to decend the hill at. I set mine at 45 or lower. The computer will shift transmission and modulate the engine brake between setting 1-2-3 to hold your set speed. If you hit the foot brake it will cancel out the hill decent mode and you'll either have to reset it or go down the rest of the way manually.

Also I believe the lightweights have a smaller engine than the full-size, so your engine brake will have less torque. You may want to set it at a lower speed to compensate.

I only had to go down that hill once while it was wet and foggy. I just went very Very VERY slowly.

Anticipate snow or ice on that hill? F that I'll be at the rest area or one of the truck stops up the road waiting for conditions to improve.

Do they have one that says “I BARELY survived...”? Lol Well now I know what all the fuss was about. No wonder Rainy was on me like white on rice about being overconfident! Thank you all again for all the sage advise.

PS. That’ll be me parked right next you in bad weather PlanB!!

So you enjoyed Cabbage hill, did ya? Lol. Your Jakes are most effective at higher RPMs 20k is normal. I know it sounds like the engine is gonna explode, but before it gets too serious, the truck will tell you to lower your rpms.

You have 2 options.

1) engage your Jake's and start down the hill. Once you get to your safe speed, engage the cruise. Your Jakes will try to keep you at our below that speed.

2) start down the hill and engage your Jake's. ALWAYS start at level 1 and go up. Don't just slap them on to level 3.

As your speed decreases, let off a level of Jake, until you start to pickup speed again. If level 3 of the Jake won't hold or slow you enogh, apply firm brake pressure for approx 3 seconds, and release. And I mean firm. By 3 seconds you should slow down approx. 10 mph. The truck may even drop a gear, and the rpms will jump up. (Don't worry about that)

In the winter, it is a judgment call. If the weather is so bad that you can't use Jake's, you may want to consider shutting down. If you can't, just remember to keep it slow. It's easier to slow a slow truck, than to slow a fast truck. As far as the other drivers flying by, drive your own truck, don't just them get under your skin. Put on your flashers, and take the hill at YOUR COMFORT LEVEL.

As far as the other drivers flying by, drive your own truck, don't just them get under your skin. Put on your flashers, and take the hill at YOUR COMFORT LEVEL.

Would you please send my trainer a letter to this effect? A forged DOT emblem would really help make the case!

Diver Driver wrote:

Your Jakes are most effective at higher RPMs 20k is normal. I know it sounds like the engine is gonna explode, but before it gets too serious, the truck will tell you to lower your rpms.

You have 2 options.

1) engage your Jake's and start down the hill. Once you get to your safe speed, engage the cruise. Your Jakes will try to keep you at our below that speed.

2) start down the hill and engage your Jake's. ALWAYS start at level 1 and go up. Don't just slap them on to level 3.

As your speed decreases, let off a level of Jake, until you start to pickup speed again. If level 3 of the Jake won't hold or slow you enogh, apply firm brake pressure for approx 3 seconds, and release. And I mean firm. By 3 seconds you should slow down approx. 10 mph. The truck may even drop a gear, and the rpms will jump up. (Don't worry about that)

In the winter, it is a judgment call. If the weather is so bad that you can't use Jake's, you may want to consider shutting down. If you can't, just remember to keep it slow. It's easier to slow a slow truck, than to slow a fast truck. As far as the other drivers flying by, drive your own truck, don't just them get under your skin. Put on your flashers, and take the hill at YOUR COMFORT LEVEL.

Above is totally, 100% spot-on!

Splitter don't fret when the R's approach 2000...you're not going to break your motor at that level.

Diver's description of alternating the Jake between medium and high is very good advice.

This is awesome advice, I got to watch the video before going out with my instructor and wondered if it really worked that way.

You guys rock!! Had to put all this great advise to good use this entire drive today. Picked up in Burbank, WA heading to Detroit. Of course that means driving across I-90. I lost count how many times I had to test all the recommendations you posted. With great results, we’ll except I got a message that my RPM’s got up to 2300!! Yeah well, it’s either that & reigning it in with the service brakes or smoking them like I did on Cabbage. Again, totally grateful to all of you for helping a brother out!! Should be less stressful here on out, I’m 30 miles outside of Bozeman. Everyone stay safe & God bless.

I'm not familiar with other makes and models of trucks, I'm in a '17 Volvo, but my trainer taught me on the principle that if you have to touch the brakes at all you're going down the grade too fast. I haven't run Cabbage yet but I've done Grapevine, the whole mess on I5 north of Redding, I15 into LA, and I70 into and out of Denver repeatedly but I've taken all of them with 70,000 lbs give or take without touching the service brakes except as maybe a final adjustment when I great a hill. (Not trying to sound contrary to anyone, I don't know if the setup on other trucks makes this harder to manage and/or figure out)

I'm not familiar with other makes and models of trucks, I'm in a '17 Volvo, but my trainer taught me on the principle that if you have to touch the brakes at all you're going down the grade too fast. I haven't run Cabbage yet but I've done Grapevine, the whole mess on I5 north of Redding, I15 into LA, and I70 into and out of Denver repeatedly but I've taken all of them with 70,000 lbs give or take without touching the service brakes except as maybe a final adjustment when I great a hill. (Not trying to sound contrary to anyone, I don't know if the setup on other trucks makes this harder to manage and/or figure out)

As long as I slow down and set my hill decent speed at the top of the hill I've never had to touch the service brake. Cabbage, Grape Vine, Snoqualmie, Donner, Vail Pass, Fancy Gap, Black Mountain, Mounteagle, set the hill decent around 35-45 and the truck handles them all.

It's 40+ miles of downgrade heading west over Donner Pass and I never had to touch the service brake.

Of course this is all in dry conditions.

Early on in my team training phase during winter I was decending one of the hills on I-80 in Wyoming and manually using light engine brake when the tires broke traction and the truck started jackknifing. I killed the engine brake and managed to counter steer and got the truck straight again. Went down the rest of the hill at 10-15mph using intermittent service brake only.

Plan B had an experience...

Early on in my team training phase during winter I was decending one of the hills on I-80 in Wyoming and manually using light engine brake when the tires broke traction and the truck started jackknifing. I killed the engine brake and managed to counter steer and got the truck straight again. Went down the rest of the hill at 10-15mph using intermittent service brake only.

Bumping this post. Glad this turned out okay Plan B.

Even "light" Jake in snow can cause things to go wrong, very quick.

Apparently I’m still learning or my engine’s compression isn’t as strong as in the condos. This learning curve is no joke though!