A 10-speed transmission in one of the most common and simplest to shift in tractor trailer trucks. Much like the manual transmission in a car, the shifting pattern in most big rigs is designed in a standard “H” format. The major difference is that in big trucks there is a lower and upper or high range. Transmissions with more then 10 speeds also have an additional splitter. Driving a semi requires the driver to downshift, which isn’t as common when driving a car or other smaller vehicle with a manual transmission.
Idle the engine long enough for the vehicle's air pressure to reach its operational range. Insure the selector button is set in the low-range gear pattern. The button should be in the down position to be in the low range.
Depress the clutch and shift into second gear. Low and first gear are not typically required unless the truck is stopped on an incline or is loaded heavy. Likewise the truck will not require the driver to press down on the accelerator to start the truck moving forward. Release pressure on the clutch slowly until the truck begins moving. Gradually accelerate while watching the tachometer.
Shift into the next higher gear once the rotation per minute (rpm)s are about 1,200 to 1,300. To shift more effectively, depress the clutch just enough to disengage the transmission remove the shifter from the gear position and release the clutch. Depress the clutch again as the rpms drop and gently place the shifter into the next gear position. This method of shifting is know as double clutching and will help to increase the long-term life of your transmission.
Repeat Steps 1 through 3 through the low-range gears. Prior to shifting into the first gear in the high range, flip the selector button up to preset it for the next gear change.
Double clutch and place the shifter into the next gear. The purpose of the high range gear selector is to allow the driver to continue to reuse the same gear positions without having to move the shifter into a pattern that would require the shifter to end up in a position that would be difficult to reach.
Downshift the truck. Downshifting is a little more difficult than shifting up through the gears. You perform much the same procedures, however, just before shifting down into the next lower gear you will need to tap the accelerator to raise the rpms. The rpm of the lower gear is higher then that on the higher gear and to successfully downshift you much get the transmission and engine speed to match. Remember to flip the selector button back down for the low range prior to attempting to shift into the gear.
Shifting gears properly takes patience and practice, but don’t get upset if you have problems with it as many seasoned truck drivers will still grind a gear from time to time.
Operating an 18-wheeler or any big truck equipped with a 10-speed transmission requires training, practice and repetition. Be especially careful when operating a big truck in mountainous areas, as missing a gear can quickly result in an accident. Also be careful when driving in adverse or winter conditions.