What is the reason for sudden abnormal noise when shifting from P to R gear when starting the car?

[MorganFitz]

The reasons for sudden abnormal noise when shifting from P to R gear when starting the car are as follows: Gear shifting mechanism noise: The car's gear shifting structure consists of the gear lever, cables, gear selection and shifting structure, shift fork, and synchronizer. The noise from these parts is relatively small. Transmission noise: Long-term use of transmission oil can lead to sludge buildup, increasing the wear of friction plates and other components. Wear in these parts can cause malfunctions and abnormal noise. If the noise during gear shifting is small and comes from near the gear lever, it is normal noise from the gear shifting mechanism. If the gear shifting produces a 'clicking' sound, it is caused by gear impact failure in the transmission.