To fix them, you just need to clean them. The simplest way to do this is by washing them. Get a deep bucket, fill it halfway with water, and put some clothing detergent in it. Pull out as much of the seatbelt as you can and put a binder clip at the end where it hangs from the car’s C-pillar to prevent the belt from reeling back in.

Get the folded part of the belt away from any guides or other thin access points and unfold it. Make sure everything is running in the same direction and the same side faces up all the way from the panel to the buckle without any twists. Release, and the retractor should take care of the rest.

Summary: Loose seat belts can be a dangerous hazard while driving. To fix them, the first step is to locate the buckle and anchor point of the belt. If you find damage, replace the components with new, reliable ones. Once all parts are in good condition, check that they are securely fastened and secure them if necessary.

The reason many people have a loose seat belt is that the seat belt won’t go in, or retract, properly. There are several different solutions to this problem posted online. Some people recommend disassembling the actual seat belt retractor and manually rotating the spool.

Loosen a retractable seat belt. If your belt is pulling you too tightly, part of it is probably stuck. Since each make and model is assembled differently, read your car user's manual for specific instructions. In many cases, pulling on the shoulder strap while the belt is unbuckled will do the trick.