How to Shift Gears on a Big Rig

The Cabin Of A Semi-Trailer Truck

In order to legally operate a semi-trailer truck or "big rig," you must have either a Class A Commercial Driver's License (CDL-A) or a CDL Learner's Permit (with mandatory supervision). However, should you find yourself in some kind of emergency situation, you'll need to know the basics of shifting a manual transmission on a diesel truck. Otherwise, you run the risk of incapacitating or seriously damaging the engine.

Instructions

Shifting Up to a Higher Gear

1. Check to make sure that the tachometer dial on your dashboard reads 4,000 rpm or above. If the tachometer is below this range, shifting up isn't recommended.

2. Completely release the accelerator pedal--the one furthest to the right.

3. Press down and hold the clutch, which is the pedal furthest to the left. Immediately grab the handle of the stick shift, depress its release button and shift the transmission to "Neutral."

4. Release the clutch pedal and allow the engine to slow until the tachometer reading drops below 4,000 rpm.

5. Press down and hold the clutch pedal. Immediately grasp the stick shift and shift from Neutral to the higher gear.

6. Simultaneously release the clutch and press down on the accelerator. The transmission is now running on the higher gear.

Shifting Down to a Lower Gear

1. Release the accelerator pedal.

2. Press down and hold the clutch while you move the stick shift to neutral.

3. Release the clutch and press the accelerator until the engine speeds up to 3,000 rpm.

4. Simultaneously release the accelerator pedal, press down the clutch and shift to the lower gear.

5. Simultaneously release the clutch and press down on the accelerator. The transmission is now ready to run on the lower gear.

References

• IowaDOT.gov: "Commercial Driver License Manual" (Pgs. 17-18)