How to change twenty gears, courtesy of Mack

Kinja'd!!! "Cé hé sin" (michael-m-mouse)
10/29/2014 at 10:27 • Filed to: None

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Here we find a Mack twin stick arrangement. Two boxes, a main with five speeds and an auxiliary with four. Neither with synchromesh naturally. Each of the five main gears could be split in four by the auxiliary box so in principle twenty forward gears were available to you. Sounds difficult? It gets worse. Because of the time taken to shift two slow sets of gears one at a time, during which time a heavily laden would truck would lose so much momentum you wouldn't need a higher gear any more, the experienced driver would use both hands, putting the further one through the spokes of the wheel and hoping nothing untoward came his way on the road. At moments like this it was convenient to have the typical build of a truck driver because if you sat sufficiently close to the wheel you could use your belly to hold the wheel in place.

So we start off with both levers in their lowest gears (although in practice you wouldn't normally need the lowest of the auxiliary gears) and we then proceed using our auxiliary lever until we reach 1(4). We then need both hands to change to 2 and 1 in the main and auxiliary respectively and proceed again, hoping that our little hands off episode at the controls of a large truck hasn't gone horribly wrong.

Think that's hard? There was a three stick arrangement...

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DISCUSSION (9)


Kinja'd!!! Cé hé sin > Cé hé sin
10/29/2014 at 10:28

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Yes, hand through wheel. Hit a large pothole and break your arm...


Kinja'd!!! Hahayoustupidludditeshutupandgohandcrankyourmodeltalready > Cé hé sin
10/29/2014 at 10:30

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It would be really fun in a masochistic way to drive one of these for a day and hope you didn't kill somebody.


Kinja'd!!! Dukie - Jalopnik Emergency Management Asshole > Cé hé sin
10/29/2014 at 10:32

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Fuck that noise. I'm glad I only had to deal with a damn 10-Speed in an old GMC Topkick from Seattle to Boise a few summers ago. This would've been hell on Earth!


Kinja'd!!! Rock Bottom > Cé hé sin
10/29/2014 at 10:34

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There's so much mechanical advantage in the steering on these things that the force of a massive pothole is pretty small by the time it gets to the steering wheel...

If you look for videos of twin-stick shifting your brain will hurt! These guys that did it a lot are incredible to watch.

Related: Youtube "Cornfield Corvette" for a good time!


Kinja'd!!! Cé hé sin > Rock Bottom
10/29/2014 at 10:37

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Allegedly it really did happen. The steering is by its nature very low geared (power steering? What's that?) so that a small deflection of the road wheel would translate to a large movement of the steering wheel.


Kinja'd!!! Rock Bottom > Cé hé sin
10/29/2014 at 10:41

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Right, but that means that large motion comes with a small force. That being said, I can see that if you were unlucky enough to have a bony arm that's in a position that allows the wheel to get a good run at ya, I can see it happening. I'd be pissed!


Kinja'd!!! RamblinRover Luxury-Yacht > Cé hé sin
10/29/2014 at 10:46

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So very much worse than the shifting Clarkson faced in the lorry challenge.


Kinja'd!!! crowmolly > Cé hé sin
10/29/2014 at 11:29

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At what point to I yell EAST BOUND AND DOWWWWWN ?


Kinja'd!!! Cé hé sin > RamblinRover Luxury-Yacht
10/29/2014 at 12:12

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You haven't seen the three lever variety yet I take it?

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