Creep groan noise is often generated when the brake pedal is slowly released in an automatictransmission car that is initially stationary; it can also be induced in a manual-transmission vehicle on an incline. The stick-slip phenomenon between the friction material and the rotor is the source of creep groan noise, which is caused by the difference between the static frictional coefficient and the dynamic frictional coefficient. Suspension characteristics are also significant contributors to creep groan. In fact, sometimes they are not just the transfer paths of the vibration, but also causes of it.
Pinjie Zhang, Lijun Zhang, Deljan Meng -, Tongji University