On a car with standard or manual transmission, the driver has to manually shift into first gear and then after the car starts to roll, the driver has to shift manually into second, then third and so on as the speed of the car increases.
An automatic transmission meanwhile allows the car to change gear ratios automatically to shift from first, second, third and so on. The automatic shifting is made possible thanks to the series of valve and switches that control the hydraulic pressure. Most cars in the market now are available in automatic transmission.
If the automatic transmission has a problem, you will notice that when you accelerate from a stop, the transmission does not shift to the next higher gear. The car seems to be dragging even though the engine speed increases. You can hear the engine screams louder than usual but the car does not really move smoothly.
This is because if there is failure in the transmission control system, the transmission stays at the low gear and the car is moving faster than it should in the low gear or first gear so loud roaring sound can be heard from the engine.
If you put the automatic transmission selector at the "Drive" position, the normal shift from the first gear to the second gear occurs when the speed of the car reaches sixteen miles per hour. If the transmission does not shift, the engine speed will keep on increasing but the car will still not gain its normal speed.
The first thing you need to do is to check the level of the transmission fluid. Top up with the correct type of fluid if you found that the fluid is at low level. When checking the level, check also the color of the transmission fluid on the dipstick. Light green or red means there is no major problem with the transmission system but if the color is either dark brown or black, the car will need major transmission repairs.
Some cars come with an additional device installed on the transmission known as a modulator where it will create excellent vacuum to make the transmission works correctly. The transmission will not shift or there will be delay in the shift if the vacuum hose is disconnected or blocked. Just highlight this to your auto mechanic if you are not sure if your car is equipped with the transmission modulator.
Apart from the above, it is also possible that the problem with the transmission comes from a misaligned, disconnected, bent or broken transmission-shift selector linkage. This means the position indicated on which gear you are on is not tally with the actual transmission gear.
On some cars, the shift point, which is the exact speed where the transmission shift, is controlled by a cable. The transmission will not shift appropriatively if the cable is disconnected or broken.
The tips above can certainly help you before you agree with the auto mechanic for any major repair on the transmission system.