Hi my name is igor im 17 and i bought a 1999 volvo xc70 cuz i always loved this car, anyway, i have a weird problem. Whenever i put the car in reverse and start turning the wheel while reversing there is a pretty loud bang/boom sound in the back end. It sounds like metal disconnecting, sliding across other metal and snaps into place again, the whole thing takes about a second, if i creep backwards it sometimes takes even about 2 sec, however when it starts even if i try to stop the car it always has to finish the "process". This happens only once, after that i can keep tuning the car right and left on reverse and nothing happens. Also nothing happens when i backup with straight wheels. When i drive forward and turn there is also barely noticeable ticking noise in the back. Sorry for a lot of writting but i wanted to be descriptive because 2 mechanics were not able to figure out what this can be, they only give me maybe or multiple options and since im 17 i dont have money to change something i dont need. Thank you for reading and please help.