A commercial driver is accelerating a loaded tractor-trailer on an expressway merge lane and prepares to upshift from 6th to 7th gear as the tachometer reaches 1,800 RPM. According to standard commercial vehicle operating procedures, which action correctly coordinates the clutch, gearshift, and engine speed during this upshift?
- ADepress the clutch pedal completely to the floor to activate the clutch brake, guide the shift lever directly from 6th into 7th gear, and smoothly release the pedal while applying throttle.
- BPush in the clutch and shift to neutral, release the clutch while pressing the accelerator pedal to rev the engine, then push in the clutch again to engage 7th gear.
- Push in the clutch and shift to neutral, release the clutch to allow engine and transmission gear speeds to decrease, then push in the clutch again to shift into 7th gear before releasing the clutch and accelerating.Answer
- DHold the clutch pedal fully depressed while guiding the shift lever from 6th gear through neutral and directly into 7th gear, allowing road momentum to equalize transmission speeds.
Answer
Push in the clutch and shift to neutral, release the clutch to allow engine and transmission gear speeds to decrease, then push in the clutch again to shift into 7th gear before releasing the clutch and accelerating.
Proper double-clutch upshifting requires releasing the accelerator, depressing the clutch, and shifting into neutral; then releasing the clutch to allow the engine and input gear RPM to drop to the lower speed needed for the higher gear; and finally depressing the clutch again, selecting the higher gear, and smoothly engaging the clutch while reapplying throttle.
Step-by-Step Solution
Key Concept
Double clutching mechanics and RPM synchronization during upshifting
Estimated Time:1m 30s