If it's "bouncing" after bumps like a boat, then yes, the shocks are probably bad. Test it out on a speed bump... roll over the bump with enough speed to compress the springs (maybe 5mph) without using brakes and see if it goes boing-boing-boing. Shocks in proper working order will just compress and rebound while a lot of "bouncing" indicates that the shock is no longer able to control the spring action.