"Cé hé sin" (michael-m-mouse)
10/28/2014 at 15:35 • Filed to: None
2
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"Cé hé sin" (michael-m-mouse)
10/28/2014 at 15:35 • Filed to: None | 2
| 7 |
Americans like to do things differently from the rest of us and this includes the activity of changing lots of gears.
This knob attaches itself to an 18 speed transmission which could just as easily be a 13 speed. The principle is easy enough for those who have been paying attention to this little series. A four speed plus crawler main box, two ranges and a splitter. The crawler is only usable in low range so we have five low range and four high range and all can be split giving eighteen. If you haven't paid enough the splitter only works in high range depriving you of five speeds and leaving a diminished tally of thirteen.
So far so good. The complications start when you want to drive a vehicle thus equipped because there's a problem. The North American truck market still buys non synchromesh gearboxes which in much of the rest of the world died out shortly after the flood (well, about the 1990s). Older drivers will remember being taught to double declutch when dealing with this kind of box, but Americans are instead encouraged not to use the clutch at all.
You start off then and when the need for higher gears presents itself - which doesn't take very long when you have lots of closely spaced speeds - you haul the lever into neutral and pause there for a time determined by years of experience until the revs drop to what they should be in the gear that you're aiming for. If you've got it just right the lever should drop into place with little effort . Get it wrong and you'll be playing tunes on the gear teeth. If you need to split a gear you preselect the split and lift the accelerator at which point the change should take place. When changing down you'll have to increase the revs so they match the desired gear.
So there you have it. And yes, life can get even more complicated than this...
Racescort666
> Cé hé sin
10/28/2014 at 16:27 |
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As complicated as it sounds, floating gears isn't too hard. You can do it in a synchronized transmission as well but it wears out the synchronizers.
If only EssExTee could be so grossly incandescent
> Cé hé sin
10/28/2014 at 17:37 |
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More complicated? The only thing more complicated I can think of would be a triple stick. Is that what's coming next?
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Cé hé sin
> Racescort666
10/28/2014 at 18:15 |
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That reminds me that Scania are one of the few truck makers to automate their existing synchro boxes rather than do what Volvo, Merc and ZF do and design a special constant mesh unit for automation purposes. As originally introduced their Opticruise AMT automated just the gear change so you used a clutch pedal to start and then the electronics carried out entirely clutchless gearchanges. They've changed that since but you can still buy a three pedal Opticruise.
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Cé hé sin
> If only EssExTee could be so grossly incandescent
10/28/2014 at 19:04 |
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Wait and see. There used to be a twin stick arrangement...
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Racescort666
> Cé hé sin
10/28/2014 at 19:05 |
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The Eaton Ultrashift is basically exactly that. Just an automated version of their existing manual unsynchronized transmission.
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Cé hé sin
> Racescort666
10/28/2014 at 19:20 |
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I recall Eaton have tried to sell various versions of AMT in Europe but they've never been able to get past the fact that most truck makers either make their own or have long standing relationships with ZF.
wallaby13
> Cé hé sin
10/28/2014 at 21:59 |
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Simple: Buy the Volvo I-shift or Mack M-Drive.
bonus: keep wallaby13 in work.