actualy no it doesent... it disconects the engine from the transmission letting the engine spin and the tranny not... thats y u have to put ur clutch in at a stop light
or switch to neutral... u can rev ur engine and not move... i dont know jack shit about dump trucks but they might be able to do it... but in cars i know that they need to be clutched... unless u love to slip the clutch then it shouldent be to hard on the clutch if u shift fast anyway... a clutch is basicly a brake its got 2 pads that connect and turn if used right u only need to use them for fractions of a second as u let of the gas depress the clutch and shift, if ur not good enough then u run down the pads faster... anyway its bad to float so dont do it unless u wanna have some gears minus the gear part...