How to Shift an 18 Speed Transmission

If you’re new to truck driving or still considering getting your CDL, an 18 speed transmission might sound intimidating. But with practice, it will soon be second nature for you. And you may find, as many truck drivers do, that an 18 speed transmission is stronger and easier to maneuver. 

How many gears does an 18 speed transmission have?

An 18 speed transmission has eighteen different gears, but you probably will not use all of them throughout a regular day. But with that many gears, there’s an option for basically every situation you might find yourself in while driving a big rig. 

The shift pattern is like a capital H. There are three gears for reverse, three for low, and twelve regular forward gears. The gear splitter is what gives an 18 speed so many gears. Basically every main gear has a high and low range. The difference in RPMs is often less than 750, so you have a lot of flexibility with which gear is optimal for your driving situation. Although most drivers will hang out in 5th gear for the majority of their driving. 

It seems like a lot, but having so many gears enables you, the trucker, to keep the engine running at the optimal RPM in every situation. Whether you’re trying to lift a heavy load from a dead stop, going down a steep grade, or maneuvering in a packed yard, your truck can run efficiently and safely with 18 gears to choose from. 

How do you shift an 18 speed without a clutch?

You can shift without using the clutch (sometimes called “float shifting”) by bringing the engine to exactly the right RPM in neutral before attempting to complete a shift. This is something that is only done by the most skillful drivers; if done improperly, it can damage or destroy a transmission.

Float shifting is tricky. You have to make sure the pressure on the gas pedal is just right, and your timing has to be basically perfect. As with regular shifting and downshifting, you never want to force a gear change. You should be able to feel when the transmission is ready to change gears, and you should only need slight pressure on the shifter. 

Is it hard to shift an 18 speed transmission?

It’s not hard to shift an 18 speed transmission, but it does take practice. Every truck is different, and they all shift just a little differently. Take the time to get to know your truck, your brake pedal, your clutch pedal, and your engine. If you’re driving a new truck, it’s a good idea to take some time outside of your regular route to get a feel for the air brakes, manual transmission, and gear shift. Practice driving in a higher gear and a lower gear, if possible. That way, when you get out on the road in your commercial truck you’ll already know the sweet spot for that tractor trailer.

Once you know the basics of shifting an 18 speed transmission, the key is to practice. The trucker uses second gear, third, fourth, and fifth gear, then splits up into high range and then shifts the H pattern again for sixth gear, seventh, eighth and ninth gear. After reaching ninth gear, split up to overdrive for the top gear. Shift smoothly. Feather the clutch and the fuel to slide the truck into gear. Never force it. 

Learning to shift an 18 speed manual transmission is essential to your career as a class A CDL driver. And it’s a big change from driving a manual transmission car. But with lots of practice and patience, you’ll be a pro in no time.