If the car has to be towed, make sure the wheels that drive the car are the ones that are lifted off the road. This is because most cars beside Mercedes do not have lubricant moving through the automatic transmission when the engine is off. That means that if the car is towed, the moving parts in the transmission will be destroyed. For some cars, this is not the case, for instance, four wheel drive vehicles that have a transfer case for high and low range, four wheel drive or two wheel drive, have a neutral position that will let the vehicle be towed and not hurt the transmission. A few front wheel drive cars with automatics are designed to be towed with the drive wheels down on the ground.

If you are missing reverse gear, but the car moves forward, you should be able to drive it to the repair shop. If you step on the accelerator and the car does not move in forward or reverse (and you are sure the parking brakes are off), it could be low transmission fluid, or it could be internal problems. If it is low fluid, just put some more in, but the question is where is it going because there could be a leak and the problem will just reoccur. Look for a thin, red colored oil on the ground. That is transmission fluid

If there is no up shift, this means the car will not go into high gear, the problem may be a minor one, such as a bad vacuum hose, cable, switch or a roang adjustment. If you drive the car to the shop like this, be aware that the engine could overheat, and do not drive faster than the maximum speed the engine would normally have for that gear. There can also be problems with the servos in the transmission that select gears. What might happen here is the car goes off slowly because the transmission does not shift into a low gear. Depending on the transmission make, this might be inexpensive to fix by just pulling the pan on the bottom, but then again, it could call for pulling the transmission. Another item that might fail causing slow acceleration is the torque converter.

A car can also be slow to accelerate if the torque converter has gone bad. If the car acts alright after it gets moving, it probably is the torque converter, so get it to a shop. Tell the technician the symptoms, does it happen when the car is cold or hot, when you accelerate, just starting off or any peculiar noises. A quick and accurate diagnosis saves you money. A shop has the equipment to check the electronic sensors that give information to the on board computer that controls the engine and transmission shifting. Gauges can also be used to check hydraulic control pressures that operate servos and clutches that engage gears for shifting. A well equipped shop will have test equipment that makes a recording of sensor output and can play it back after returning to the shop. Some abnormalities are so transient that they cannot be detected in actual time while underway.

If the car will not come out of park, do not use so much force that a shifting cable or linkage gets damaged. Fords made in the 1970s and 1980s have this problem as does some late model Chrysler front wheel drives.

Another consideration with a manual transmission is they are cheaper to build and more reliable. In the past, manual transmissions used less fuel, but modern automatics have a mechanism that makes them like a manual transmission at road speeds. This is called a lockup torque converter and it is nothing more than a clutch inside the torque converter that makes the automatic like a standard transmission with a clutch by freezing the insides of the inefficient torque converter.

An automatic can fail suddenly. A manual transmission can go a million miles and the only part of the system needing repair is the clutch. A clutch job is usually much cheaper than an automatic transmission rebuild, and happens about as often. Also, a clutch will not usually fail catastrophically so that you need a tow. The exception might be if the engine speed is increased to a very high and the clutch suddenly engaged. This could break gears, but a similar tactic with an automatic transmission called a neutral drop (into gear with high engine speed) will just about guarantee catastrophic failure. A transmission mechanic can tell if this type of abuse has caused transmission failure. If that is the case, be aware that the guarantee on a rebuild most likely will not cover this kind of abuse if you bring the car back after doing the same thing again.

If you get stuck in snow, mud, or sand, and the bottom of the car is not resting on the snow, mud, or sand, you can dig yourself out by making a path for the tires, kind of a ramp. If you are up to the frame, you can call a wrecker, or you can jack up the vehicle and fill the holes under the tires. Do not slam the vehicle into drive and them reverse trying to rock the vehicle out. You will dig yourself deeper. This is also as hard on the transmission as winding the engine speed up and dropping the car into drive. You will destroy the transmission.

I have seen experts in off road travel rock a vehicle, but this is the gentlest of procedures, a slow movement back and forth, causing the tires to make a ramp in the soft material instead of getting out of the vehicle and using s shovel to build the ramp. Also, if you are on snow, spinning the tires heats them up and makes the snow even more slippery because of water on snow. The colder the weather, the better the traction because less water is formed between tire and snow from pressure of the tire on snow.

The transmission fluid and filter need to be changed just like a car engine. The way to tell when to change the fluid is by the color of the fluid. It will be red when new, then fade to pink to as it oxidizes, then when it reaches a pale yellow, it is time to change it, before acids form in the fluid that are destructive to the transmission. The older fluids form varnish on parts that cause slippage, and the fluid looses its ability to lubricate. When the time the fluid smells liked burned toast, there is definitely  a problem. By the way, formation of a deposit in the bottom of the transmission pan that looks like silver paint is harmless and is from normal wear. If there are discernable lumps you can feel, then it is time to worry.

Heat is what sends a transmission to the shop 90% of the time according to the Automatic Transmission Association, a trade group that keeps transmission mechanics informed about special problems and fixes for their profession.  If you have a transmission with a hard to fix problem, and a transmission mechanic belongs to this organization, you have a better chance of getting the problem fixed.  Only about ten percent of the failures of automatic transmissions with less that 100,000 miles on them are from something other than heat failure.  Engineers design a transmission to have a normal operating  temperature of 175 degrees F. At 250 degrees, the rubber parts are going to loose flexibility resulting in control servos that leak resulting in slippage when the car starts up cold in the morning.  At temperatures higher than 250 degrees, the clutches and bands start to slip causing imminent failure.