Automatic Transmission vs. Mountain - Question

Kenworth with the Ultrashift I'm assuming?

I tend to use the manual mode down hills, but you don't have to. If you are in the correct gear, and you can select the correct gear yourself even in auto mode, it tends to stay there.

And if they are using the cummins, I can usually go down hills at least one gear higher than I would go up them, but again, that's something you'll have to figure out for yourself.

Just remember that you can't be afraid to shift on hills. They don't really miss shifts, unless something is going wrong with the transmission. Experiment with it as much as you can so that you'll understand how it shifts and how everything works so it doesn't do stuff unexpected.

 

auto shifts are still manuals just with a auto shift feature being controlled by a computer, stick it in manual and go one gear lower just to be safe.

 

tons of time in all 3 autos, they are designed to hold you in place (even if manual is disabled from the company). you can always upshift or downshift via the "stick" even with no manual mode enabled

come over the top of the hill, at the speed you want to go down it. get down to the gear that you want to be in. (it should be close, you're doing the speed you want to, it's probably in too high of gear. Whack the "stick" a few times and get it up into that 1800rpm range (really, they all want to be here) with the jakes on "full" (or high however you choose to think of it)

now, let the jake run (and maybe service brakes) and get 3 to 5mph BELOW what speed you want to go down the hill in. This both lets the cruise overrun work and ensures that the jake will hold you in the right gear. (if you speed up, you need to slow down more and get down another gear or two, but all of the newer autos and engines have amazing jakes. even freightliner (finally).

now, set the cruise control.
DO NOT TOUCH THE THROTTLE . They will all up shift in auto if you give it throttle.

all the way down the hill right at the speed that you set or it will run up to 3 to 5mph an hour so.

This is not a set and go take a nap thing, you're heavy and going down a serious hill. if you start picking up speed, you WILL run out of rpm and you'll need to stab brake to get it down and then probably stab brake a few more times to be able to grab another lower gear. The big advantage of an auto on a downhill is you'll never miss a downshift. You should be able to run most any hill without touching the service brakes, even at 80k and 7%.

You're not setting the cruise you're setting what freightliner calls descent control (and they all have the same thing). you're off the throttle and it's not giving it any throttle but it's balancing the act of jake, engine speed, traction, etc. The volvos and freightliners do this better than the Eaton auto. (KW/PB/Int). if you hit a flat spot (vail pass westbound, perfect example) it will just keep slowing down, and you'll have to give it throttle which will cause it to upshift. (stupid fuel economy idiocy). Which requires you to reset it, grab the lower gear again and hit resume, but it keeps you from changing the jake settings, etc.

Uphill is where auto's suck. They keep upshifting instead of holding a gear because obviously it's UPHILL and going to be for miles. I use manual much more on uphills than downhills. Downhill, using manual and the cruise control thing above will work too but lots of companies have manual disabled. (you know for fuel economy so you can crawl up the big hill in 6th at 30mph instead of 9th at 55mph. idiocy)

 

That engine brake on the auto KW is awesome. Put it on high and it does all the work for you. The transmission will downshift once you apply the brake as well.

 

I was issued a 2001 Century with the 500+ Detriot and a rockwell Auto on it in 2001 with about 16 miles on the ODO for team work.

It featured a paddle with the standard PRNDL Low is for mountain work but the paddle also manually changed gears when RPM is appropriate to the one you want for a variety of reasons, particularly mountain work downgrade or even upgrade to keep the pyro cool.

We ran team in the rockies all that year and then some all over with it. Learned that you need to shut the truck down at least 4 hours per 7 days so it will flush the software buffer. If you run it that hard 24/7 never stopping or shutting engine off, it had a habit of blue screening or bricking. Turning the whole thing into a useless vehicle requiring a heavy recovering wrecker to fetch it. Twice that year. THAT's expensive.

Manual was useful in snow. But once we were west of Knoxville with 7 in convoy as number one. The rig hit a left leaning curve upgrade by a canyon in those days at about 24 or so with spouse driving. It instantly hit that ice and went into a tractor jack knife. Which would be her first. I basically hopped up onto the dash and grabbed the wheel to adjusted it a few inches enough to get the drives back biting into that hill and pulling. Told spouse to do nothing but stay right there like a statue. The automatic took care of that problem which would have been quite something for her if it was a true manual transmission. We clawed out of there at 7 mph or so while number two broke his traction and the rest went into the canyon in the middle. One backwards using power to stay upright. (Hats off to that ballsy driver. Protect the load...)

It was a tiny little snow. A bit of ice. about two inches. Hardly worth mentioning. A slight trifle compared to say wyoming. But it was a real big day. (A bad one for some)

We got about 7 miles to gallon give or take filling 300 gallons every 30 hours or so plus reefer. We did not give a #### about fuel mileage. But once in a while it turned in computer real time fuel mileage records in certain situations that were pretty impressive when the winds were right.

We put 221000 on that thing in about 9 months wore it straight through, fixing to get another new team tractor and break that one in cherry. But we moved on to hauling medicines with another company contracted to McKesson. That was pretty much the end of our automatic adventure.

The one thing Rockwell and Detriot did correctly was tuning for shifting. Every time shes working hard and I think it was about a month before I quit reaching for the shift that was not there anymore on that floor. Right then she is shifting properly. That is one of the reasons I loved it so much. For what it was. FFE issued it to us to make sure that spouse can do a good job driving forward and never mind the rest.

I'll die with a manual transmission in my hand for a variety of strong reasons. But as I watched autos evolve or become badly configured or even mis equipped with manual options removed etc over the next few years as a crew boss leading a team of temp CDL drivers. Teaching manuals to those who don't know it and autos to those who don't know it and sometimes reaching back even further to drive really old iron myself at auction. So I had a chance to witness first hand how it evolved. Some well, some badly.

The next thing I noticed was that you no longer were a driver taking care of the information from 60 or so gauges all over that cab. It's now just a speedo, rpm and something for your air and fuel. Reducing you to a rather... not needed part of actual driving a semi anymore. Mindless comes to mind is the word.

Anyhow. My story is strictly my own. Unique. People will have trouble with it. And that's fine. As far as I am concerned I no longer worry about autos too much PROVIDED they have a PROPER MANUAL mode for mountain work and that it is tuned well enough to the engine ont hat rig.

As far as stab braking, set the jake up properly in one gear mostly all the way down and let her run out at the bottom is fine. You don't touch nothing unless you really have to. You will find with a good jacobs, the right gear and RPM for it the rig will be balanced all the way down with small variations as she goes.

I don't have anything else to offer you because mountains is my specialty. You earn each one as you cross em. Any one can go up. It takes a trucker to get back down correctly.