What is the most common failure in automatic transmission?

The most common fault in automatic transmissions is shift shock or jerking, manifested as noticeable vehicle vibration or rough power delivery during gear changes. Primary causes include degraded transmission fluid, malfunctioning solenoid valves, internal valve body wear, and worn clutch plates. These issues are particularly prevalent in Malaysia's hot and humid climate, where high temperatures accelerate fluid oxidation and rainy conditions may allow moisture ingress through transmission vents. Manufacturer-specified transmission fluid should typically be replaced every 40,000-60,000 kilometres, with avoidance of prolonged high-load driving in congested traffic. Notably, approximately 70% of transmission failures originate from improper maintenance. If accompanied by oil pan leaks or metallic noises, immediate servicing is crucial to prevent gear train damage, with repair costs potentially reaching RM2,000-5,000 depending on affected components.