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Foreign Trucks | |
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by TFLYTSNBN » Fri May 15, 2020 1:11 pm | |
TFLYTSNBN
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I've been shopping for a new semi tractor. I was raised on Cab Over Engine trucks. They have serious manauverability and safety advantages. I am mystified by the American preference for very long wheel base semi tractors that have the engine sticking out, then the cab, then the sleeper, then ten or fifteen feet of empty space before the front of the trailer. They ride gentler, but not that much gentler.
COE, heavy duty trucks are no longer available in America. The last COE semi Tractor in America was the Freightliner Argosy. I have been shopping for used Argosys. Most of the listings are from Australia, South Africa or New Zealand. I noticed that almost all of the Australian trucks have 18 speed transmissions. Typical, modern US semi tractor is a ten speed or nine speed if not an automatic. Thirteen speed transmissions are old school from the golden age of 250 horsepower. Why 18 speeds in a truck with over 500 horsepower? Answer. Australia allows very long, multiple trailer combinations. They often weigh 70 tons rather than the 40 tons which is standard in America. I will concede that Australia has it right on this. |
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Re: Foreign Trucks | |
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by Daryl » Fri May 15, 2020 6:23 pm | |
Daryl
Posts: 3562
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Called a Road Ranger gearbox. Two gearlevers, so you could say go 1-1, 1-2, 2-1 or whatever. I've used it in big tractors ploughing, but not on the road.
We have road trains in the outback, where four trailers are pulled by one prime mover. As you get closer to civilisation the length drops. B Doubles are allowed, a half length trailer and a full length one, quite a handful in traffic. |
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Re: Foreign Trucks | |
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by TFLYTSNBN » Sat May 16, 2020 3:40 pm | |
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The modern Roadranger transmissions have toggle switches to activate air actuators to select range and split gears. As intimidating as they might appear, I would rather drive triple, 12 meter trailers than double 8 meter trailers that are common in the US. Far less stable. |
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Re: Foreign Trucks | |
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by Odium » Sun May 31, 2020 12:47 pm | |
Odium
Posts: 30
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I’ve been driving truck for 13 years now. Mainly off pavement in the oil fields of northern Alberta, Canada. I’m not sure why you dislike 18 speeds, of the 30 or so heavy trucks I’ve driven in my career 1 had a 13 spd, 1 was a 10 spd, all the rest were 18’s and I vastly prefer that transmission. It’s not as though you need to use all the gears, when hauling empty I’ll often go 2H to 4L to 6H to 8H, 3 shifts from dead stop to highway speed. But when I’m axle deep in mud trying to climb a 10+% grade with 100,000lbs on I’m damned happy to have the extra gears. I’ve never actually had the chance to drive a cab over, but I’ve always heard from the people I know that ran them that they were a horrible ride. I’m pretty used to poor maneuverability (my current truck I run is a tridrive that’s 45’ bumper to bumper and weighs over 20,000lbs on the steers, 20 pt turn arounds are standard for me)
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Re: Foreign Trucks | |
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by TFLYTSNBN » Sun May 31, 2020 8:30 pm | |
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I don't dislike 18 speed transmissions. I'm just not certain that they are needed when a standard American semitractor and semitrailor are limited to 40 tons. As you point out, you are free to skip a lot of gears and the extra low gearing is useful off road. |
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Re: Foreign Trucks | |
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by Castenea » Sat Jun 06, 2020 1:50 pm | |
Castenea
Posts: 671
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I know from both driving things a little smaller than OTR Semis, and observation that there are two things behind the prevalence of 18 speed transmissions in American class 8 trucks. The first is tradition, there are a lot of truck drivers that learned by driving an 18 speed and think that any real truck has one. The second is that the 18 speed (and 10 and 13 speed E-F transmissions) was designed when one of the more common engines in heavy trucks was the Detroit 71 series, which both needed to be wound up to get into it's power band and had a short power band. Thus a trans mission that had 250 RPM between shifts was needed to keep the engine in the sweet spot for usable torque. |
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Re: Foreign Trucks | |
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by TFLYTSNBN » Sat Jun 06, 2020 3:45 pm | |
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The first semitractor that I drove was an old Consolidated Freightways, single axle Freghtliner with a 8V-71 Detroit Diesel with only a 5 speed manual transmission with only one range and no splitter. It was a real screamer. |
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Re: Foreign Trucks | |
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by Castenea » Sun Jun 07, 2020 5:55 pm | |
Castenea
Posts: 671
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Could that screaming jimmy with that trans set up even get the rig to 45 MPH? |
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Re: Foreign Trucks | |
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by TFLYTSNBN » Wed Jun 10, 2020 8:32 am | |
TFLYTSNBN
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Yep! |
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