What are the symptoms of a damaged AT automatic transmission?
4 Answers
AT automatic transmission damage may manifest as abnormal noises, overheating, or slipping issues. Below are detailed explanations: Transmission Abnormal Noises: Symptoms: Unusual sounds or loud noises from the transmission during idling, driving, or under high load, with irregular, dull noises during gear shifts. Causes: Prolonged high temperatures degrade the transmission fluid's anti-wear and lubricating properties, leading to wear or severe damage to bearings, gears, or gear surfaces. Action: Consult transmission specialists immediately for professional advice before proceeding. Transmission Overheating: Symptoms: The computer alerts to high transmission temperature while driving, or the transmission feels excessively hot to touch after driving. Causes: Inability to effectively control temperature under high load, or slipping can cause overheating. In some dual-clutch transmissions, friction from clutch plates during low-speed crawling generates excessive heat. Action: Pull over and let the vehicle rest for a few minutes before restarting. Seek professional repair if the issue persists. Transmission Slipping: Symptoms: Engine revving without corresponding speed increase when accelerating (similar to pressing the throttle in P or N gear), or normal driving on flat roads but poor uphill performance with high engine RPM. Causes: Excessive hydraulic fluid creating bubbles when agitated, or worn/burnt clutch/brake friction materials.
The most obvious symptom of a faulty AT automatic transmission is severe gear shifting jerks, where accelerating during normal driving suddenly feels like someone kicked you. Last time on the highway, I experienced the throttle being pressed, the RPM soaring, but the speed not increasing—this is a classic slipping phenomenon. Sometimes, there’s a delay of about ten seconds when shifting gears; even after shifting to D, the car just won’t move, which is incredibly frustrating. If you hear clunking metal impact sounds, stop and check immediately—it’s likely a gear issue. The most critical thing to watch for is the transmission warning light on the dashboard; if that yellow gear symbol lights up, head to a repair shop right away. Transmission fluid leaks are also common—if you see red oil stains under the car, don’t hesitate, get it fixed promptly.
Problems with automatic transmissions often start with subtle symptoms, as I've learned from twenty years of driving experience. The car lurches forward when starting, and the RPM suddenly jumps during acceleration—these are early warning signs. The most annoying issue is needing to warm up the car for three minutes before it can shift gears after a cold start, especially noticeable in winter. I've encountered transmission oil leaks, leaving small red stains on the parking spot, a clear signal of aging internal seals. The most dangerous situation is during highway overtaking—the engine roars but the speed refuses to increase. Modern cars have a protection mode; if the transmission fails, it locks into a single gear, leaving you no choice but to crawl to the repair shop.
The most dangerous automatic transmission failure is gear shift jerking. It feels like being rear-ended while driving normally, with the tachometer jumping erratically during acceleration. Reverse gear often produces clicking noises, and sometimes there's a delay of several seconds before power engages when shifting to Drive. Slippage is especially common when using air conditioning in summer - you hear the engine rev but the car won't accelerate. As a mechanic, I often see transmission fluid leaks everywhere, easily identifiable by that sweet smell and red stains. Experienced drivers know to watch the dashboard - when that yellow transmission warning light comes on, trouble is brewing. Severe failures can cause transmission lock-up, preventing the car from exceeding 60 mph no matter how hard you press the gas.
