2002 CLK seatbelt does not retract
 

I have cleaned the seatbelt as best I could using simple green (its pretty dirty)...but I am not sure where to go from here.

It does not retract at any reasonable speed. If you leave it overnight it will return, but its hardly acceptable or safe. I can manually feed it in and it retracts fine, but left by itself it does not do it. So I am not sure anything spring-wise is broken...but I am not sure since I have never dealt with a seabelt before.

How can I get it fixed? Anything to be concerned about on these later models with airbags going off if I take the mechanism apart or replace the belt?

Any help or suggestions on this issue? It is next on the list to fix now the wagon's A/C is functional!