I have a 1987 "420SEL" and I just had my timing chain, front left bushing, ball joints and engine mounts replaced. On my drive home from the mechanic, I hit a slight bump at 50mph and I felt a bad vibration in my front left side and the steering wheel. It scared the crap out of me and I had to drive no more than 40mph for fear of getting the bad vibration. I can't return the car until tuesday morning to the mechanic. What might this be?