What Causes Abnormal Noises Outside the Vehicle When Shifting an Automatic Transmission?
4 Answers
Automatic transmission shifting noises can be caused by damaged solenoid valves, burnt friction plates, or failure to replace transmission fluid regularly. Below are detailed explanations: Damaged Solenoid Valve: A faulty solenoid valve can result in excessively low or high oil pressure, causing the clutch or brake to engage with noticeable impact or delay, thereby generating abnormal noises. The solenoid valve needs replacement. Burnt Friction Plates: Burnt friction plates not only cause abnormal noises during gear shifts but also lead to jerking and poor driving performance. The friction plates require replacement. Failure to Replace Transmission Fluid Regularly: If the automatic transmission is not maintained for an extended period, the lubricating effectiveness of the fluid significantly decreases, increasing friction between gears. This accelerates gear wear and causes abnormal noises. Regular transmission fluid changes are necessary.
I drive quite frequently and have encountered abnormal noises outside the car when the automatic transmission shifts gears. The sound resembled metal scraping, especially noticeable when starting from a stop. After some research, I learned it might be due to improper gear meshing during transmission shifts or insufficient lubrication from low fluid levels. Additionally, worn-out rubber components or loose ball joints in the suspension system can also cause creaking noises during power transitions. Later, at the repair shop, I found that a screw under the chassis had loosened, and tightening it solved the problem. I recommend getting it checked early to prevent minor issues from turning into major repairs. After all, driving safety comes first. A friend of mine ignored similar sounds and ended up with a ruined transmission, which was extremely expensive to replace.
When encountering such abnormal noises, I usually first check the condition of the transmission fluid. Low or dirty fluid can easily cause clunking sounds during gear shifts. Next, I inspect the chassis components, such as whether the exhaust pipe brackets or engine mounts are loose. These parts can produce rattling noises when shifting if they become loose. Worn suspension links or bushings are also common culprits. I once had a car with this issue, and replacing the parts fixed it. It's best to use a jack to lift the car and check for any wobbling. If you're handy, try tightening the components yourself; otherwise, take it to a professional repair shop for diagnosis with specialized equipment. Remember, don't ignore abnormal noises, as delaying repairs could affect other systems, and towing fees aren't cheap.
When I was a novice driver, I also encountered external noise during gear shifts, which felt a bit scary. Simply put, it could be due to certain parts being broken or loose, such as excessive wear of gears in the transmission, or loose screws in the chassis suspension. Temperature changes can also affect it, especially in winter when metal contracts and the noise becomes more noticeable. My suggestion is to start with the simple things: first, check if there are any obviously loose parts in the chassis, and see if the exhaust pipe is aged or cracked. If that doesn't help, ask a car-savvy friend to take a look—don't force it to avoid damaging the car. Fixing it isn't difficult, and minor issues can be repaired for just a few dozen bucks.
