Company removing manual gear selection override on automatic trucks?

It can get hairy at times, especially when empty and roads are wet. Just have to do a balancing act with engine brake and service brakes.

 

The Detroit autoshift will always stay in gear anytime you touch the brakes or step on the throttle. It will also keep the RPM near governor to get the most braking power from engine. That's why in stage 3 it will downshift to bring RPMs up. 1750-2300 RPMs

If you don't need or want that much braking power stage one and two keep RPMs 1400-1700. You can play around with it and downshift or upshift anytime you want in automatic mode.

So if you want more braking power you can just flip the switch to stage three and let the computer downshift and it will bring RPMs up automatically. You can also set Jake's at stage one or two and downshift anytime you want

Once you hit the brakes the cruise control cuts off. So your in control of the transmission at that point.

 

Here's what drivers need to know about Detroit autoshift. The engine brake is set up for maximum braking power and the computers are designed for this.

So if your going downhill and you turn on stage thee engine brakes the engine and transmission work together to bring RPMs up to 1750-2300. Here is the different part, the autoshift will always keep the RPMs in 1750-2300 rang. So if you don't to anything the truck will keep slowing down from 65mph all the way down to maybe 15 mph. Using full engine brake at stage 3. It will keep downshift gears at 1750-2300 RPMs to keep giving you the driver maximum engine baking power. Because that's what you are telling the truck you want.

If you don't need maximum braking you can set stage one or two. Then the truck will keep engine RPMs in a rang of 1300-1750. Then same thing the truck will keep slowing and downshifting in that RPM rang from 65 mph all the way down to 15 or untill you turn engine brakes off.

So to stop the autoshift from downshifting all you do is take your foot off the brakes and let the truck roll and gain speed and engine RPMs. When your going to fast you tap the brakes and slow down.

So if your going downhill at 55mph with stage three engine brakes you will see the RPMs dropping to 1750. At that point you have thee options take you foot off the brakes let the truck roll a so rpm go up because you don't want to go slower then 55. You can switch to stage 2 engine brakes and truck will stay in gear and keep rolling because stage two and one are 1750-1300 RPM. You can also do nothing because you want to go slower and at 1750 RPMs the transmission will downshift and keep slowing truck untill you tell it to stop slowing truck or till you get down to like 15MPH

 

My company has the company spec automatics locked into economy mode with manual mode deactivated. You can force it to shift with the paddle but then it will do whatever it wants to do.

Jake's are extremely powerful compared to our previous trucks. Easily hold 55mph at 80k on a 6 or 7 percent downgrade.

Scares the hell out of me on ice. Will constantly switch into e-coast on downgrades. The first time I encountered this I wound up turning it to the lowest Jake setting for fear I was going to burn the brakes up.

Contacted our freightliner rep and we are supposed to hold down the brake pedal just enough to keep it from coasting and he advised it would not burn the brakes up if speed was appropriate. I've tried this a few times in good conditions and it definitely requires enough pressure to show on the applied pressure gauge. No way in hell I am going down from the Eisenhower tunnel doing this in ice. Predict we will shut down in a lot of situations we never did in the past.

Maybe if it gets someone killed they will enable manual mode again. We had the computer go nuts and autoshifting went out once, it's horrendous shifting with the paddle manually. I don't think it would get abused much.

This is the d12 transmission on a dd15.

 

What you describe fits to a T why my buddy prefers the manual over ride in snowy/icy conditions. It also explains why I turned down the job offer from Quality Logistics in Denver. I talked about this on page 1 of this thread.

I'll never forget what the guy at Quality Logistics said: "having a manual mode defeats the purpose of having an automatic."

I beg to differ. A manual option complements an automatic, as in it makes it complete.

Some of these desk jockeys in charge are not nearly as smart as they think they are. In my experience, they usually got their cushy jobs by family ties, or blind luck, or the ability to suck up to the right people and back stab those who can't hurt them. Or even a combination of the three.

For them, here is a lesson in probability: PRIOR to EVERY catastrophic never-seen-before event, smug little fools relied on the belief that because such an event had not occurred in the past, it therefore cannot occur in the future.

After the Space Shuttle Challenger disaster in 1986, which resulted from arrogant upper-level managers dismissing the possibility of o-ring failure, you'd think NASA would know better.

Fast forward to 2003. Linda Ham, a key manager involved in the Space Shuttle Columbia Mission, decided against investigating the possibility that faulty foam can destroy the shuttle upon re-entry. She wasn't a monster. She was just arrogant and foolish.

If she had the wisdom to take the cautionary approach, the Columbia could have stayed in orbit until the Atlantis could reach her to transfer the crew. Another back up plan would've been to make repairs while still in orbit. Both options were not without risk. But they were significantly safer than the decision made by upper management at NASA.

And the results? Columbia tragically exploded upon re-entry. Seven dead astronauts, millions spent in investigation, and a mere demotion for Ham.

Go through history and you'll find this pattern over and over and over again.

What does faulty o-rings, foam, and space shuttles have to do with the subject, you ask?

If top-level managers at NASA, an organization which deals with travel and logistics at the highest level, can fall victim to stupidity and hubris, what does that say for the typical operations manager at a trucking company...?

Does this mean every automatics out there are rolling time bombs? Of course not.

However, I won't be shocked if we see day when a tragic confluence of poor road conditions + software glitch + inability to manually over ride (and maybe factor in under trained driver who relies solely on the computer) = Devastating Loss.

And when the dust settles, maybe, hopefully, people will realize that "Ah - human experience, instinct, and intervention ARE important!"

 

I have question if driving on ice, snow or slippery roads, why are you using the engine brakes ?? You know you are not suppose to do that.

 

I will have to experiment with this as I find myself constantly flicking between engine brake settings to maintain a constant speed downhill.

If you know of a way to prevent the economy roll from kicking in with engine brake off (I don't have manual mode) I would be eternally grateful. Many times just leaving truck in gear with no engine brake would control speed enough, but the economy roll kicks and away I go.

 

If going downhill just just push the brake pedal my truck will stay in gear anytime you put on the brakes and anytime you turn on engine brake. So pick stage one or two f you don't need three. Or if light loaded don't use any and just use the truck regular brakes and it will stay in gear. You don't even have to worry about economy roll because if you start going to fast tap the brakes and it will engage transmission or manual turn engine brake on and it will engage transmission

Here a little trick some else said. You can set the cruise control for 6MPH less the speed limit because on my truck anyway the auto Jake will come on at 6MPH over set cruise speed. Or just let truck roll 6MPH over speed limit the autoshift and auto Jake will kick in and downshift if needed to keep truck within 6MPH of set speed. Let the computer and transmission do it thing and see if it can hold truck back at 2200 RPMs

 

I was hoping there was a way to keep transmission engaged without using the brakes. Probably won't hurt anything but I don't like the idea of keeping my foot on brake pedal.

On my truck I can set cruise braking for 6 or 4 mph over set speed...or switch off cruise braking completely. The thing is there may be times when I don't want any engine braking at all like when empty on slick roads but my only option at this point is constant foot braking or hair on fire eco roll.

 

The CDL manual advises Snub braking not constant light pressure braking they used to teach.

It the unit is designed for only Auto mode then that may be the only choice to prevent it from upshifting to the top gear. The other choice is to use the jakes which will continue downshifting til the driver touches the throttle to upshift again.

Autos were supposed to take the thinking out of truckdriving instead a driver will have to pay triple attention to avoid going into a jackslide.

All this 2200 rpm talk lol come back and tell me in a couple years how many turbos you've gone through.....