nikb

Dear friends , I have a gl 450 2007. Off recently when i am coming to a stop sign or a complete stop.i hear a whoofing/scuffing sound. it is similar to the whoof from the airride system that i hear once in while when the vehcile is parked. only this is louder. I have also experienced this when going through a pot hole once in a while.
Originally it was a occasional noise and now it is almost there every time i am about to come to a stop.
i am confused . Is -It something serious like issue with transmission or something else. I have been ignoring it as i cant distinguish if it is the air pump or something else.
any thoughts or feedback and help is welcome and appriciated.