Manually shifting gears in a Kenworth truck can be difficult until you get the hang of it. Inaccurate shifting wastes fuel and can damage transmissions. Grinding occurs when the gears rub together if the clutch is not fully engaged or you do not synchronize your transmission speed when you shift. The Kenworth Corporation and Eaton Corporation teamed up in 2010 to add the Eaton UltraShift as an option for all of Kenworth's Class 8 trucks, but many purchasers still choose manual transmissions because of personal preference and cost.
Release pressure on the accelerator.
Mash the clutch down far enough to engage it. The clutch pedal will have about an inch of play before you feel resistance. After you feel the resistance, push the clutch another 1/2-inch to open the gears far enough for them to change.
Push the gear shift out of the current gear.
Let off the clutch while you watch the tachometer fall to 500 RPM. The RPM drop depends on the engine and transmission in your Kenworth. Consult your owner’s manual to determine the correct drop.
Re-engage the clutch.
Push the gear shift into the next gear.
Press on the accelerator to increase the speed.
Perform the first three steps in Section 1.
Let off the clutch and apply pressure to the accelerator to raise the tachometer to 500 RPM.
Release the accelerator and re-engage the clutch.
Use the gear shift to put the truck in the next lower gear.
Being able to shift gears without grinding requires miles of practice. Do not let a bad shift upset you; they happen to everyone.
As your ability to shift gears increases, try skip shifting. When you skip-shift, you skip gears as you move through the gears. Remember to increase or decrease the amount of RPM change in correlation to the number of gears you skip. If your Kenworth requires a 500-RPM change and you skip one gear, it needs a 1,000-RPM change. If you skip two gears, it requires a 1,500-RPM change.
If you cannot find your gear, put your flashers on and bring the truck to a stop. If you are frantically trying to find the gear you need, you are not paying attention to the traffic around you and could cause an accident.
You will hear drivers speak of floating gears or shifting gears without using the clutch. Using the clutch relieves pressure on the transmission parts and provides smoother shifting, lessening the chance of transmission damage.