Before you take your car to a mechanic for problems with the transmission and gearbox, you might want to consider what could be causing those problems so you have a better idea of the repairs you might be facing.
Because the transmission is such a major component of your car, you need to ensure it's in good repair but don't want to overpay for repairs that aren't needed. Note some common transmission and gearbox problems you might face.
1. The transmission is stuck in Park
In many cases this isn't the transmission itself that is breaking down, but is often caused by a chain inside the gearbox which is connected to the pedals of the car. Most cars have this chain installed so that you cannot take your car out of gear if your foot is not on the brake pedal. If this chain should break, you cannot move your shifter in the gearbox as it's not getting that signal that your foot is on the brake. This chain is usually a simple and affordable replacement.
2. The transmission shifts slowly or the gears slip
When you move the lever in your gearbox from one gear to another, it should change immediately rather than your engine revving and your car not moving as it should. Your gears should also never slip into Neutral or from one to another. The most common cause of this problem is a fluid leak in the transmission lines. Seals in the gaskets that close up the transmission itself may become loose and allow fluid to leak out.
However, if your car's transmission fluid levels are normal then you want to check the solenoid. This is a part that controls the flow of fluid through the transmission lines. The solenoid can become damaged due to contamination in the lines or due to an electrical problem. Your car may have sufficient fluid but if the solenoid is not delivering it through the transmission lines, you'll have the gear shifting problems mentioned above.
3. The car shakes when you put it into gear
This is typically a problem with the clutch, which is in the torque converter of your car. When the clutch is jammed, the car is trying to move forward or backward but cannot, which in turn causes the shaking. If you notice that the car shakes and you seem to have lost pickup in the engine as well, this is usually a sign that the clutch is jammed or worn out and needs gearbox repairs.