Whether you own a manual transmission or an automatic, it must change gears when you drive it. If your transmission is kinda stuck in gear, or won’t come out of park, then there’s definitely a situation. The actual reason will vary depending on other signs and information – whether the gear is stuck in park, whether you’re driving an automatic or a manual, and many more.

How this system operates:

Both manual and automatic transmissions are complex and need a significant number of parts in order to operate. Of course, automatics are the more complex of the two systems. However, your issue might have nothing to do with the transmission at all. Forexample, if you can’t shift out of park with an automatic transmission, chances are good that the issue lies elsewhere, perhaps with the brake light switch connected to the brake pedal.

In a manual transmission, changing gears needs a working clutch pedal, clutch and other parts. You depress the clutch pedal, which engages the clutch and stops the transmission from spinning with the engine. This makes you to shift gears. Sequencers lets you to shift smoothly into each gear.

Additionally, there’s the situation of your master cylinder if you have a hydraulic clutch (some vehicles have a clutch cable, but some are hydraulic and will have a fluid-filled master cylinder and slave cylinder that must be functional in order to shift gears, or the vehicle will act like the clutch pedal isn’tde pressed).

In an automatic, the transmission handles all the work for you. All you have to do is press the accelerator, and the transmission will shift on its own as your speed increases. This needs a number of parts not found on a manual transmission.

Common reasons why this happen:

  • *Low Fluid in Transmission– Both manual and automatic transmissions need fluid (different types) in order to operate normally. If the fluid is low, there’s a possibilty that you won’t be able to change gears, particularly in an automatic transmission. This also produces immense damage to the transmission itself. However, it’s more likely that you would be able to shift, but the transmission would not move the vehicle.
  • Low Fluid in Master Cylinder:If you’re driving a stick shift gear and it has a hydraulic clutch, one of the first thing to check is low fluid in the clutch master cylinder. This is generally caused by a leak in the system (you may observe fluid on your clutch pedal).
  • Broken Clutch Cable:If you have a cable-operated clutch, it’s equally possible that the cable has broken. If the pedal goes to the floor without engaging the clutch, this would the one of the primary causes.
  • Failed Brake Light Switch:If you’re not able to shift out of park with an automatic transmission, the most likely culprit is the brake light switch. It’s located on the brake pedal and designed to engage the shift lock solenoid if it notices that your brake lights aren’t working.
  • Bad Sequencers:If you’re able to shift out of a gear, but when you attempt to shift into the next sequential gear, you hear a grinding sound, chances are good that the sequencers are going bad or have failed. You should be able to shift to the next highest gear without trouble if this is the issue.

How it’s done:

The mechanic will verify that the vehicle’s transmission will not shift. This may need a test drive (if the transmission will not shift while moving). The mechanic may also have to pull diagnostic codes from the car’s computer via the OBD II connection under your dash.

How important is this repairs?

If your vehicle will not change gears, there’s a significant issue and you should not attempt to drive the car. Regular maintenance can help stop issues like this, including master cylinder inspections, fluid changes and more.