Prime Inc Is Disabling Manual Mode On Their Trucks With The D12 Manual Automatic Transmission !

Knight is starting to disable thiers as well. I absolutely hate automatics. They are junk and it's going to make me quit being a company driver

I trained at Prime Inc on a 10-speed manual transmission and drove about 6 months solo on one until they put me in a new truck with the D12 transmission. I hated it at first but I ended up driving 519 K miles in it and I got pretty used to it. I got to the point where I could take steep downgrades fully loaded without touching the service brakes by downshifting to lower gears in manual mode and engaging the Jake brake, including in the winter. Well now, they’ve put me in a new used truck and the first thing I noticed was the manual mode didn’t work. I took it to the shop to get repaired and was told that Prime is purposely disabling the manual mode ! This makes no sense to me and in fact I think it’s dangerous. The D12 is called a Manual Automatic Transmission. The manual mode was put there by the manufacturer for a reason. By not having it available, it discourages the use of the Jake Brake because whenever you do use it, the truck wants to immediately downshift by 2 gears and there you are over RPMing. In manual mode, you simply put it in the gear you want and you work the Jakes all the way down the mountain and you maintain a steady speed and RPM. I can’t imagine what it’s going to be like out in Wyoming going over Elk Mountain next winter. Has anyone else heard of a company tinkering with the basic controls of the truck like Prime Inc is doing ?

People sure do have some strong feelings about these Auto Shift transmissions!

They've never bothered me. I sure wouldn't call them "junk." I am mostly familiar with the I-shift Volvo transmission, but that thing works wonderfully.

You guys do know that you can turn off E-Coast on Freightliners??? Settings menu buried in there. Have to manually turn it off every time you start the truck other wise it defaults on.

Ironically, Wilson has that disabled, but still allows the use of manual mode. Now if only they'd set the cruise control over/under speed to less than 5 over set speed before it starts slowing you down.

Running at 65 it'll give you an overspeed before slowing you down if you try to let it work as intended.

I trained & drove a stick shift. Swift switched me to auto shift. I don't care to go back. Give me automatic!

Learn to use the Jakes in the new system. You'll be spoiled.

Knight is starting to disable thiers as well. I absolutely hate automatics. They are junk and it's going to make me quit being a company driver

I trained at Prime Inc on a 10-speed manual transmission and drove about 6 months solo on one until they put me in a new truck with the D12 transmission. I hated it at first but I ended up driving 519 K miles in it and I got pretty used to it. I got to the point where I could take steep downgrades fully loaded without touching the service brakes by downshifting to lower gears in manual mode and engaging the Jake brake, including in the winter. Well now, they’ve put me in a new used truck and the first thing I noticed was the manual mode didn’t work. I took it to the shop to get repaired and was told that Prime is purposely disabling the manual mode ! This makes no sense to me and in fact I think it’s dangerous. The D12 is called a Manual Automatic Transmission. The manual mode was put there by the manufacturer for a reason. By not having it available, it discourages the use of the Jake Brake because whenever you do use it, the truck wants to immediately downshift by 2 gears and there you are over RPMing. In manual mode, you simply put it in the gear you want and you work the Jakes all the way down the mountain and you maintain a steady speed and RPM. I can’t imagine what it’s going to be like out in Wyoming going over Elk Mountain next winter. Has anyone else heard of a company tinkering with the basic controls of the truck like Prime Inc is doing ?

Interesting, I get my truck next week and I havent seen evidence of Knight disabling it yet. But Im new. I do know that even at 79k I barely had to use service brakes at all unless I started out with too much speed. There were a few places where I had to stab break to get it to shave RPMs but not often. As far as I know, if we exceed 2300 rpm, we get a message to reduce it and reduce speed. Anyway the most action I saw out of shifting in manual mode was to make the truck start in 2 or 4 to keep it smooth when taking off out of a rough parking lot. Im not opposed to using manual mode but I also get around just fine without it. I dont know much as I said, Im new, but the tranny sure seemed to work ok to me. I dont really think shifting a manual in LA traffic sounds like fun itinerary Just my 2 cents worth.

Reply to Turtle: So my understanding of descent control from reading the trucks owners manual and watching some videos from Freightliner is that you slow down, engage the engine brake and set the cruise control. How do you use cruise on snow and ice ?

I don't use descent control or cruise on snow and ice, preferring instead to use slower speeds and controlled braking.

Ok.... Let me explain...this is not a case of a company "disabling a truck and making it unsafe".

If you watch the freightliner videos....this is the "Economy Fuel Saving" option designed by the company. It is kinda like choosing between a 4cyl, 6cyl or V8. Neither is unsafe.

I have only had 2 autos, both internationals and both had the manual option. In 3 years of driving them I never once used the manual option so no they arent necessary.

There is an auto class in the springfield terminal to teach you about the truck. Call the training department to inquire. We also have fleet reps from every make to answer questions.

On your phone app you will find the freightliner rep under "My Contacts" feel free to call that specialist and ask for help. There may even be an auto class on our app under "educational videos"

I was terrified of the auto too before I switched from a manual.

As a tanker I live by manual mode when taking off, especially when starting going up a hill. The economy mode that is default wants to skip shift because the way the liquid surges. This causes issues if it skip shifts from say 2-4 when taking off the truck will wont have enough power to move and you will come to a dead stop as the transmission finds the right gear now that the liquid has surged back onto the drives. Even Peterbilt has said “the way Prime has the ecm programmed for tankers is killing these trucks.” I’m l/o so I will still have my manual mode, but company tankers deal with chaos multiple times a day.

Crete has the manual mode disabled which I very much dislike with this 12 speed transmission. I have asked for the next new truck I'm loaned for 450K miles to be a 10 speed manual.

Noob question: if the manual mode is disabled and you're descending steeper grades in snow or rain w/o jakes, won't it keep trying to shift to higher gears on you as the truck accelerates?

I'd read about making sure to be in the correct gear for the grade from ahead of time to avoid accelerating too fast and burning up the service brakes.