Squeaking while driving and loud bobbing at the start

Hello, Unfortunately my US forum could not help me here. I drive a 1968 Buick Riviera, recently the following problem occurs: At 2 exits I now had the problem of having a squeaking high-toned even grinding appearance only during the return rides. The longer I drove this was all the louder. When rolling slowly at a traffic light as it goes off Rattert it to the very loud metallic. Unfortunately, the sounds are hard to describe. wheel bearing, cardan shaft or brake?