My 02 reg E320 (71 000 miles) has used the inside shoulder of its tyres very heavily. The tracking appears to be fine (runs straight). When I was getting the tyres changed, I asked the tyre-change chap to check for any play. There was noticeable in-out play when holding the top and bottom of the discs (wheels off). It was more noticeable when the wheels were back on. Does this mean BOTH front bearings are on their way? Could it be ball joints? If it is bearings, can they be tightened (taper bearings), or are they pressed types? Please help!