My outdrives are shaking. the outside ends of them where the bone goes in are doing circles instead of staying in one place. is this normal, or is my diff messed up? it also looks as if the bones dont go into the outdrives as far as they did before.... anyone have ideas? i am going to take it apart soon but idk what to look for, this is my first rc car

my buddy that knows everything doesnt know anything about gear diffs