When I started with my current company in August 2005, they gave me a 1999 Volvo with a 10 speed Rockwell. I found that it shifted better/easier than an Eaton (no idea why; but I drove trucks with manual Eatons before). As a highway driver I spend most of the time cruising on the highway, with the cruise control on; so the manual is okay. Where you have to "work it" is on hills (when the engine bogs down and you need to downshift) and in big cities - in traffic. That's why you see big trucks crawling slowly in jams - drivers don't want to shift every single minute!
My second/current truck is a 2005 Freightliner Columbia with a Mercedes engine and a 10-speed SmartShift. There's no clutch. It's naturally much easier to drive, especially on hills: with the cruise control on, the tranny switches itself to the proper gear by itself. However, when I drive in heavy traffic - the auto can be quite annoying. First of all, it doesn't allow me to go from 2nd to 3rd below 1500 rpm (with a manual I can shift at 750 rpm); and then when you slow down the engine revs itself up all the time... I try to change to semi-auto mode ocassionally, but it's not much better...
Some other problems with automatics: if you have an engine brake on, and you stop - let's say - on a red light somewhere, the tranny will not upshift properly. It'll rev up to 1800 rpm, and then - after a few agonizingly loud moments it'll finally shift itself into ... a 3rd.
I think the problem is there's just too much torque in the diesel engine (unlike in a car), and that what causes problems. It'll take years before auto trannies in trucks will work as flawlessly as in cars.
Sometimes, after you shift (and the gear number is seen on the display, which means you're in gear), nothing happens - you push gas ... and then the truck lunges forward. The same thing happens when you try to back up: it's either stopped or goes too fast.
So, basically it's been my experience that auto trannies give you LESS control of the truck. They are good for city trucks - for someone who deals with heavy traffic all the time... I think highway drivers can be okay with a standard...
Another thing.. if you get a used truck with an automatic, and it breaks down, it may cost much more to fix the tranny. Standards are easier to fix.
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