How to Shift Peterbilt Trucksby Sam Grover
Many semi trucks, Peterbilts included, have manual transmissions. This forces the driver to focus more and also gives him more control over the engine. If you shift a manual transmission correctly, the fuel economy will be substantially better than with an automatic. The key differences between Peterbilt transmissions and those in automobiles are that there are more speeds in the truck and the clutch has a clutch brake to stop the engine from moving.
Turn the engine on and let it idle until it reaches 1,000 rpm on its own. This is particularly relevant in cold weather. Also, if the weather is cold, press the clutch pedal, put the gear stick into neutral, and release it to warm up the transmission as well the engine.
Press the clutch pedal all the way down when the Peterbilt is stopped. This will activate the clutch brake, which will stop the gears from moving while you connect the transmission gear to the engine gear.
Move the gear stick into the first gear position.
Release the clutch brake and release the clutch until the truck starts moving forward. You will not need to depress the gas pedal to start the truck moving.
Release the accelerator and press the clutch down once you are ready to shift into second gear. Make sure you don't press it all the way -- the clutch brake is only necessary when the truck isn't moving.
Shift the gear stick into neutral and release the clutch.
Let the rpm drop a little bit so that the engine doesn't lurch when you shift into second gear.
Press the clutch pedal again and move the gear stick into second gear. Release the clutch and continue driving.
Continue this process through the rest of the gears.
Downshift when you need to by following the above procedure, but pressing the accelerator when you are in neutral to match the engine's rpm to the lower gear.