Warning! The noises that occur when the seat belts are retracted are caused by the automatic belt retractor mechanism. Never lubricate the mechanism to eliminate these noises. As a last resort, replace the seat belt with another one. Do not disassemble the automatic seat belt retractor mechanism, as this may cause the compressed spring to jump out. Risk of accident!
1. Pull the seat belt completely out of the retractor. Check the belt webbing for torn fibres. Damage can occur, for example, due to the belt being pinched or from a burning cigarette. In this case, replace the belt (see illustration).
If there are worn areas but the fibers are intact, then the belt does not need to be changed. If the belt is difficult to move, make sure that the belt is not twisted. If necessary, remove the middle pillar trim.
If the automatic retractor does not work, replace the belt.
2. Clean the belt tape only with water and soap, never use solvents or chemical cleaning agents.
[Publication reprinted from this resource MercedesMAN.ru]