Whether you have a manual transmission or an automatic, it must change gears when you drive. If your transmission is stuck in gear, or won’t come out of park, then there’s definitely a problem. The actual cause will vary depending on other symptoms and information – whether it’s stuck in park, whether you’re driving an automatic or a manual, and more.
How this system works:
Both manual and automatic transmissions are complex and require a significant number of components in order to operate. Of course, automatics are the more complicated of the two systems. However, your problem might have nothing to do with the transmission at all. For instance, if you can’t shift out of park with an automatic transmission, chances are good that the problem lies elsewhere, perhaps with the brake light switch attached to the brake pedal.
In a manual transmission, changing gears requires a working clutch pedal, clutch and other components. You press the clutch pedal, which engages the clutch and stops the transmission from spinning with the engine. This allows you to shift gears. Sequencers allow you to shift smoothly into each gear.
Additionally, there’s the question of your master cylinder if you have a hydraulic clutch (some cars have a clutch cable, but some are hydraulic and will have a fluid-filled master cylinder and slave cylinder that must be in operation in order to shift gears, or the car will act like the clutch pedal isn’t pressed).
In an automatic, the transmission does 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 requires a number of components not found on a manual transmission.
Common reasons for this to happen:
*Low Fluid in Transmission - Both manual and automatic transmissions require fluid (different types) in order to operate. If the fluid is low, there’s a chance that you won’t be able to change gears, particularly in an automatic transmission. This also causes 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 car.
Low Fluid in Master Cylinder: If you’re driving a stick shift and it has a hydraulic clutch, one of the first suspects is low fluid in the clutch master cylinder. This is generally caused by a leak in the system (you may notice fluid on your clutch pedal).
Broken Clutch Cable: If you have a cable-operated clutch, it’s possible that the cable has broken. If the pedal goes to the floor without engaging the clutch, this would the one of the primary possibilities.
Failed Brake Light Switch: If you’re unable to shift out of park with an automatic transmission, the most likely culprit is the brake light switch. It’s mounted to the brake pedal and designed to engage the shift lock solenoid if it detects 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 failing or have failed. You should be able to shift to the next highest gear without trouble if this is the problem.
What to expect:
One of our professional mechanics will visit your home or office in order to inspect the transmission and verify the problem. The mechanic will then provide a detailed inspection report that includes the scope and cost of the necessary repairs.
How it's done:
The mechanic will verify that the car’s transmission will not shift. This may require a test drive (if the transmission will not shift while moving). The mechanic may also need to pull diagnostic codes from the car’s computer via the OBD II connection under your dash.
How important is this service?
f your car will not change gears, there’s a significant problem and you should not attempt to drive the vehicle. Regular maintenance can help prevent issues like this, including master cylinder inspections, fluid changes and more. One of our mechanics can inspect the system and determine the actual underlying cause of the issue, and then repair your car to get you back on the road.