So, you want to learn to drive the bus?

How to use this document

Anybody who is thinking of learning to drive the bus should read this document carefully. But in no way should this document be considered sufficient training to be able to drive the bus alone. Please seek instruction from an experienced bus driver before attempting to drive it yourself. I strongly encourage anybody who will be doing a lot of driving to get a commercial driver's license. While it is not legally required, the training is very relevant, and it gives you more legitimacy as the driver.

This document only describes how to drive to vehicle. It does not cover starting the vehicle, or safety checks, both of which are necessary for safely using the bus. Starting the bus is really more of a maintenance task.

The basics

On one level, driving the bus is just like driving a regular (albeit very large) manual transmission passenger vehicle. The controls are the same -- a steering wheel, a brake pedal, a clutch pedal and an accelerator pedal (not gas -- this is a diesel). You have windshield wipers, headlights and turn signals. The most obvious difference is that the transmission on the bus is unsynchronized, meaning that you need to double clutch every time you shift. More on this later.

But in another sense, driving the bus could be hardly more different. It is 35 feet long and 8 feet wide. It weighs 22,000 pounds when empty. It uses air brakes, which are extremely powerful, but lacks almost any other safety provisions. As the driver, you'll be separated from anything you hit by only a few feet of air and a thin sheet of metal. Also remember that when you are driving it, there could easily be a dozen of your close friends who have trusted their lives to you in the back.

Big diesel engines

Before discussing the transmission, I'd like to make a few notes about the engine in the bus. It is a huge powerful diesel engine, the size you'd find in some semi trucks. It has gone over 400,000 miles, and with good care could do that much again. We clearly do not care for the engine that well, but we should do our best to keep it from dying.

Large diesel engines are all rev-limited. For our bus the maximum engine speed is about 2200 RPM. The letter is not like one you'd find in a passenger car either. In passenger cars, when you go too fast they abruptly cut off the fuel, and the vehicle becomes difficult to operate. With a large diesel, it will run very smoothly against the limiter. In fact, these engines are running their best when they are running at their maximum speed.

Whenever straining the engine, such as when going up a hill, you should leave the engine running at maximum RPM. Similarly, you should never stress the engine by asking it for a lot of power at lower RPM. This is called lugging, and is the worst thing you can do for a diesel engine. More on this in the hill driving section.

The transmission

The bus uses a five-speed stick shift transmission. The gears are laid out in a slightly different manner from what you're used to in a standard double-H configuration. Be sure to look at the metal plate describing the gear placement next to the stick shift. Before you start driving, remind yourself of these differences. I have provided a diagram here for reference purposes.

Another important difference between the bus' stick shift and a standard double-H concerns the placement of springs in the transmission. There are three neutral positions for the stick to be in: the one between the reverse and first gear (the left position), the one between second and third gear (the center position) and the one between fourth and fifth gear (the right position). In a normal passenger car stick shift, there are springs which naturally draw the gear into the center neutral position, when you pull it out of any gear. The springs on the bus' stick shift are different however. There's a strong spring pushing left between center and right positions -- similar to normal cars but stiffer. There's little or no spring between left in center positions however. This is the key point.

When shifting from first gear to second gear, you perform the same action that you one in a normal car shifting from second to third. However due to the spring in a normal car, most people are used to simply pushing up to make this shift. The lack of a strong spring here means that you have to consciously move the stick to the right to get it into second gear.This is a very common mistake.

Before driving the bus, you should practice moving the stick shift around with the engine off. This will help you get a feel for where the gears are in the transmission. It is important to do this with the engine off. With a normal car, you can just put in the clutch and move the stick around all you want. But since the bus does not have a syncromesh in its transmission, you cannot do this.

The syncromesh, or lack thereof

A syncromesh is a device in a manual transmission that forces the two sides of the gearbox to spin at the same speed before the gears engage. When the syncromesh does not work properly, you hear a grinding noise when shifting gears. The bus does not have the syncromesh all. So great care must be taken when shifting gears, or else it will grind very loudly every time.

Without any automatic aid, you as the driver are completely responsible for making sure the gears are spinning at the same speed before you engage them. The grinding is bad because it scares your passengers, frustrates you, and damages the transmission. But worse than that, if you do not shift properly, you might not be able to get the bus into gear at all. When trying to maneuver in traffic, this can be extremely annoying. When driving down a hill, this mistake can be fatal.

I realize this is a foreign concept. It will take some getting used to. I don't completely understand the theory myself, but I'll do my best to explain it.

When the stick is in the neutral position, the two sides to gearbox are disengaged. When you push the stick up or down into a gear, you're moving the two sides of the gearbox together. It is during this act that you must be sure that the two sides of the gearbox are spinning at the same speed. One side of the gearbox is connected to the engine, and the other side is connected to the wheels. Between the engine and the gearbox is the clutch.

Consider what happens when you shift up a gear. Before the shift, the engine side of the gearbox is running at its top speed. But when you engage in the next higher gear, it must be running at a significantly lower speed. The reverse is true when shifting down the gears. You must get the engine side of the gearbox running at a high speed in order to engage the next lower gear.

Which gear to use

The bus has five gears, and each gear corresponds to a range of speeds. This table shows what gear you should use for any given speed.

0-14 mph	1st gear
14-28 mph	2nd gear
28-40 mph	3rd gear
40-54 mph	4th gear
54-70 mph	5th gear
70+ mph	not recommended

To avoid lugging, you should always use the lowest gear possible. That is to say, as soon as you drop below 28 mph, you should shift into second gear. Running at 20 mph in third gear is very stressful for the engine, especially up hills.

How to shift up

The bus is stopped. Put in the clutch, and slowly slide the gear shift into first gear. To start the bus from a stop, you do not need to press the accelerator at all. Diesels have an amazing amount of torque, so if you let the clutch out slowly, you will not stall. Slowly let the clutch out until it engages. The vehicle will start to move forward. Apply the accelerator, and the bus will accelerate. When it reaches about 14 mph, you will see that the bus is no longer accelerating. You have reached the rev limiter of the engine. Notice that even though the engine speed is limited, it's still runs smoothly.

At this point, your foot is on the accelerator, the clutch is out, and the stick is in first gear. To shift into second gear perform the following actions in succession:

1. Depress the clutch pedal all the way. At the same time, or immediately after, take your foot off the accelerator, just as if you're taking a moving car out of gear.
2. With the stick shift into the neutral position.
3. Let the clutch out all the way.
4. Wait briefly.
5. Push the clutch all the way in.
6. Push the stick into the next higher gear.
7. Release the clutch somewhat slowly, and at the same time apply the accelerator. This is the same motion you would use when shifting a moving car into gear.

This is known as double clutching. When the stick is in neutral, and your foot is off the gas, the engine speed slows down naturally. By letting the clutch out at this point, you force the engine side of the gearbox to also slow down. The amount of time you wait in step 4 is key. Actually how long the entire process takes (steps 1-7) is more important than the length of the pause with the clutch out.

Shifting from second to third is exactly the same, except you must do it a little bit faster. This is because the engine does not need to slow down quite so much. From third to fourth is even faster, and from 4th to 5th should be about as fast as you can shift. From first to second it should take between one and two seconds for the entire process.

Downshifting

Downshifting is considerably more difficult than shifting up. When you first learn to drive, you'll probably accelerate, and shift up. And when you need to slow down, and you'll go to complete stop at a traffic light or stop sign. Luckily, in normal driving, and downshifting is far less common than shifting up.

Let say you're driving along at 30 miles an hour in third gear, and you need to slow down a little bit. 28 mph is the shift point between second and third remember. When you start, the stick will be in third gear, the clutch will be out, and your foot will be on accelerator. Follow these steps:

1. Take your foot off the accelerator. Wait for the vehicle to decelerate to the shift point. Use the brake if needed.
2. When the speedometer reads exactly at or very slightly below the shifting speed, proceed to the next step.
3. Put the clutch all the way in, and shift the stick into neutral.
4. Depress the accelerator pedal all the way.
5. Let the clutch out.
6. Wait for the engine to reach its maximum speed.
7. Put the clutch in, but keep your foot firmly on the accelerator.
8. If the vehicle is still moving at the transition speed, you should be able to slide it into the next lower gear easily now.
9. Still keeping your foot on the accelerator, release the clutch.

   As step 8 hinted at, if the vehicle slows down too much while you're in the process of shifting, you'll not be able to get it into gear easily. When this happens, you can get "lost" between gears. The best thing to do at this point is to leave the bus in neutral and use the brake to slow down to the next lower shift point. Repeat the downshifting process there. For this reason it is very important to know where the shift points are intimately.

   Air Brakes

   The bus uses air brakes, which means they use pneumatic air power instead of hydraulic power like normal power brakes do. Unlike normal passenger cars, there is no direct connection between the brake pedal and the brakes themselves. These are not power assisted brakes, they are entirely powered.

   This might seem like a safety risk until you realize that the brakes are negatively actuated. This means that if the air system should fail on the bus, the brakes will automatically engage. If this happens, the bus will be stopping very suddenly. There is a red dongle called a wig wag in the upper left portion of the cockpit. When you start the bus, and you must reset the wig wag by pushing it up. It is held there by airpower. If the air system fails, the wig wag will fall down in front of your face, clearly telling you to stop. This does not mean you should apply the brakes, but rather that the brakes are being applied for you and you should maneuver the vehicle to the side of the road as quickly and safely as you can.

   A more fine grain indicator of the status of the air system is the meter on the right side of the dashboard. It tells you the pressure in the pneumatic system in pounds per square inch. The wig wag drops at about 60 PSI. I believe the brakes will engage automatically at somewhere between 20 and 40 PSI. When the air pressure drops below about 60 PSI, a loud buzzer will sound. You should be familiar with this sound from starting the bus.

   Whenever you apply the brakes, it bleeds some of the air from the tanks. For this reason, you should never pump the brakes as you might in a normal car. This can drain the air tanks to a dangerous level. Whenever you're braking, be conscious of the air pressure.

   Going up hills

   When driving up hills, the most important thing to remember is not to lug the engine. This means that when you're going up a hill of any size, you must do so at the maximum RPM for the engine. So, there are only five speeds at which you can go up a hill: 14 mph, 28 mph, 40 mph, 54 mph, or 70 mph if the grade is extremely shallow.

   So, if you're going up a hill at 40 miles an hour, and the engine isn't quite strong enough to maintain that speed and you drop down to 35 mph, you must downshift, lest you damage the engine. To do this, perform steps 1-6 in the downshifting instructions. Pause while you have your foot on accelerator, and the clutch out, and the stick in neutral. Wait for the bus to slow down naturally. When you reach the shift point (28 mph in this case), quickly finish the procedure by putting the clutch in and moving the stick into gear.

   If you find you cannot hold 28 mph, swallow your ego and drop down to first gear.You cannot be in a hurry when driving the bus.

   Going down hills (the engine brake)

   Driving down hills is the most dangerous thing to do in the bus. As any skilled car driver knows, you cannot rely on your brakes to slow you down for the entire extent of a long hill. If you use your brakes for long time, they will heat up, "fade", and become unable to stop your vehicle. This is especially true when driving a vehicle that weighs over 20,000 pounds.

   So if you can't use your brakes to slow down, what do you use? You use the engine. Like when driving a car, you should leave the bus in gear when going downhill. The friction intrinsic to the engine will help slow down the vehicle. The engine has a powerful water-based cooling system in the radiator to keep itself from overheating. The brakes have nothing but air flying over them to cool them off as the heat up. Also, the engine is well lubricated, so it does not wear down as fast. For these reasons, the engine is much better at keeping your speed down over extended periods of time than the brakes are. The brakes have the huge advantage that they are very fast to respond. So if you need to slow down quickly, by all means hit the brakes.

   Like most large diesel vehicles, the bus has a secret weapon called an engine brake. These are also commonly referred to as Jake brakes, and are responsible for the familiar purring sound of semis slowing down. The bus' engine brake has four positions: off, and three strengths of on. The engine brake control is a metal lever on the far left side of the dashboard. When it is pointing straight up, it is off. Rotating it to the right will turn it on. Normally you should leave this control off, since it can make the engine stall if it is on and you don't realize it.

   What does the engine brake do? It restricts the exhaust manifold, or something like that, to force the engine to spin more slowly when no fuel is applied. Most engine brakes turn themselves off when you press the accelerator. I believe our bus' does this also, but I'm not sure off hand. There's no point in having the engine brake on when you're applying fuel anyway.

   So what you do when you're approaching a downhill part of road? Slow down! It is important to be going at appropriate speed before you start going downhill, because slowing down while going down a hill is much harder than it is on the level. Remember the procedure for downshifting -- it involves waiting for the bus to slow down to appropriate speed. If the bus' natural tendency is to accelerate rather than slow down, you'll have a great deal of difficulty moving to a lower gear. The old rule of thumb is that you should go down the hill in the same gear that you went up it. Follow this rule!

   As you're approaching a downhill, decelerate and put the bus into the appropriate gear. If you're unsure that you can do this in time, just stay in gear the you're in. It is far worse to be lost between gears when going downhill than to be in a gear that is too high. If you're lost between gears, all you have is your regular brakes. If you're lost between gears on a steep hill, I recommend stopping as fast as you can to regain complete control of your vehicle, and then accelerating up to what you consider a safe speed.

   Once you're going downhill, with the engine in gear, keep your feet off all pedals. If you can do so safely, moderate your speed entirely using the engine brake. Watch the speedometer. When going downhill, it is possible to push the engine passed its maximum allowable RPM. This can damage the engine. Stay below your shift point!

   If you find that the engine brake is insufficient to maintain a constant speed, do not attempt to shift to a lower gear. Instead use the brakes. The technique you should use when going downhill his referred to as stab braking. This is a technique which is designed to keep your brakes as cool as possible on long downhill journeys. For more information, refer to the commercial driver's license guide.

   When stab braking, you select a target speed which is your maximum safe speed. Once your vehicle accelerates to the speed, you should apply the brakes firmly for a brief period of time, approximately 1 to 2 seconds. Press the brakes firmly enough to decelerate approximately five mph in this time. Then release the brake completely and allow it to cool. Wait for the vehicle to accelerate back up to the safe speed and then repeat the process. It should take at least ten seconds to accelerate up to the safe speed.

   If you're accelerating faster than this between stabs, then you're probably using your brakes too much, and they may overheat. Turn on the engine brake if you can. If this does not help, and it looks like this condition will continue for long period of time, you should consider trying to shift down to a lower gear. To do this, use the brakes to slow way down first and then accelerate up to the speed which you would need for a lower gear. Again, let me repeat, you should only change gears on a downhill if it is absolutely necessary.

   Cornering

   When cornering on the highways, or when moving at speed, remember that the bus has a high center of gravity, and can roll easily. Rolling the bus is very bad. Keep in mind that the back part of the bus will tip first, so as the driver sits in the front, you will not be aware of how much the vehicle is tilting.

   Remember that the yellow suggested speed limit signs which always seem way too slow are written with vehicles like the bus in mind. If the sign says take this turn at 35 miles an hour, then you'd better not be going any faster than that around the corner.

   City driving

   The most important thing to remember when driving in the city is that your vehicle is extremely large. Stay as close to the centerline as possible, and be conscious of where the right side of your vehicle is. If you keep your own body positioned in the lane the way you're used to when driving a car, you'll likely scrape the right side of the bus against parked cars on the side of the road.

   When turning in the city, take your turns as wide as you can. This means that when you're making a right turn, aim for the leftmost part of the lane. And when making a left turn, aim for the rightmost part of the lane.

   When turning right onto a two lane road, you'll often have to place part of your vehicle in the way of oncoming traffic. If you think that there is not enough room to make the turn without doing this, then be sure to wait until oncoming traffic is clear. You will find that making left turns as actually easier than right turns because you have more room.

   Also keep in mind that the bus' turn signals do not cancel themselves automatically when you recenter the steering wheel like a normal car's do.

   Mirrors

   Always watch your mirrors. When driving on the highway, check your mirrors every ten seconds or so. The bottom mirror on the right side should be pointed near the front right wheel. It should give you a good idea of your lane position. Normally, you should be able to see the line on that side of the road in the mirror. If you can't see it, then either the mirror is misadjusted, or you're driving on top of the line.

   General Safety

   Remember always that you're driving an eleven ton vehicle. A collision could easily kill you and many of your closest friends. Always be patient. Going somewhere in the bus will always take longer than going in a car. Do not take risks if you can avoid them.

   When driving on the highway, try to get into the habit of looking 10 to 15 seconds ahead if you on the road. This is much further ahead than most people normally look when driving cars. If you see brake lights far ahead, begin to slow down. Remember that downshifting can take some time.

   Try to avoid any unnecessary distractions while driving. If possible, find a slave to service you while you're driving. A slave should deal with the radio, music, getting you food and water, and disciplining the passengers.

   Wear your seatbelt!

   Questions? Comments

   Send them to leo@mezziah.org.