mcgovern61 » Wed Jun 29, 2016 9:11 am[/url]":4vdan8ec]
And why? What happens if you make a mistake?
The reason is you can choose which gear level is required based on a load. For example, with the cement mixer, if the barrel was empty, I would would skip all of the low low gears and actually start off in 2nd gear (which had a reasonable ratio for an empty truck). You can skip certain gears if light load.
However, when fully loaded, I might still skip low low gears when on the street, but use them when on a muddy job site where I do not want to get stuck. On the road with a load, the order is needed to keep the momentum of the truck going at the correct rate of speed to keep the transmission synchronized with the output. Gravity has fun slowing down a loaded vehicle very quickly and if you slow down too fast the synchro goes out and you end up grinding gears. You have a chance to stop the grinding if you can get the engine rpm high enough to re-synchonize, but that doesn't always work.
If you make a mistake........you grind gears and might have to start over. Also, we only used the clutch to disengage the transmission when the truck was stopped. Once moving, all shifting was done without using a clutch by syncronizing the rpm.