Signs of Car Transmission Problems

Updated July 19, 2017

The transmission is an essential mechanism in a vehicle. When this mechanism begins to wear out, cars will display warning signs of transmission failure, whether the transmission is a manual or automatic. In order to avoid transmission failure, note any signs that may indicate a problem, such as the check engine light or a transmission fluid leak. Any unusual noises coming from the transmission will also indicate a problem. Take your vehicle to a repair shop at the first sign of transmission failure to avoid costly repairs.

Automatic Transmission

An automatic transmission is a gearbox that mechanically shifts gear ratios as the vehicle picks up speed. It has a fixed amount of gear ranges and several common shift modes. The common modes include Park ("P"), Reverse ("R"), Neutral ("N") and Drive ("D"). Vehicles with an automatic transmission have a shift lever to navigate the shift modes. Since the 1950s, more vehicles have been sold with automatic transmissions than with manual transmissions.

Manual Transmission

A manual transmission requires the driver to shift gears manually with a gear shifter and a clutch. The driver must press down on the clutch, which is a pedal on the left side of the brake pedal, when shifting gears. This controls torque transfer from the engine to the transmission. The driver shifts gears based on the speed, RPMs and the sound of the engine revving. Most cars have five gears, though some vehicles are equipped with four or six gears. According to, a manual transmission provides both power and speed though selected gear sizes engineered for maximum performance.

Transmission Leaks

If there's a transmission leak in your car, you may notice some dark fluid underneath your vehicle after it has sat idle for several hours. The fluid is usually black, red or pink. This could indicate a leak in your transmission due to a broken seal. A transmission seal regulates hydraulic fluid, which limits the chances of a fluid leak.
Another sign of a faulty transmission seal is if you shift the car to the "Drive" gear and it lunges forward.
A transmission fluid leak can sometimes lead to the transmission overheating. When it begins to overheat, you will notice a burning odour.

Signs of Transmission Problems

Another sign of transmission failure is if the vehicle does not move, or if there is a delayed movement when gears are shifted into "Drive" or "Reverse." The transmission may slip out of gear, delaying acceleration; this is a common sign of transmission wear and tear. A conspicuous sign of transmission trouble is if you hear a loud knocking or any other abnormal sound. In this case, the transmission may have an issue with parts rubbing against each other, perhaps causing corrosion.
Keep an eye out for metal shavings or any other debris in the transmission fluid. This is an indication of corrosion in the transmission.
If the vehicle abruptly jerks while shifting gears, this could signal any number of transmission problems.

Avoid Transmission Problems

According to, the transmission is the most complicated mechanical component in today's automobiles. In many cases, the "Check Engine" light informs the driver when there is a malfunction developing with one of the vehicle's crucial parts, such as the transmission. Check the transmission fluid levels on a regular basis. Transmission fluid is usually a clear red colour; if it appears "dirty" or discoloured, then you must change the transmission fluid. Most transmission repairs are expensive due to the need for a precise diagnosis, as well as the parts and labour. The AAMCO official website states that because modern-day vehicles are primarily computer controlled, transmission specialists are the most reliable when it comes to adequately diagnosing and repairing a transmission problem.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Jeremy Dunn is a freelance writer from Harlem, Ga. He began his professional career in 2005. He writes on Atlanta NASCAR for a prominent website and authored the book, "Superstars of Pro Football—Ray Lewis." He has composed articles for other publications like "Speed South" magazine and "RaceWeekly" magazine. Dunn holds an Associate of Arts in printing/graphics from Augusta Technical College.