Steering

If it occurs only under moderate acceleration, suspect wear inside one of the inner cv joints but that would not be common at the mileage you listed. At 33,000 miles a broken tire belt would be more likely but you will typically also see the steering wheel move back and forth a little at lower speeds such as when driving through a parking lot.

Other potential suspects include a deteriorated engine mount that lets one side of the engine sag changing the half shaft angles, or a bent wheel. A steering and suspension inspection at a tire and alignment shop should identify the cause.