Half-shaft sideways movement causing suspension clunk

[NZ00Z3 187]

Hi

Been tracking down a rear suspension clunk in the 2.0 L Z3 (E36/7) and identified it as coming from the drivers side half-shaft.  There is ~10 mm axial movement in the shaft and it had migrated to the diff end resulting in the inside CV providing the suspension travel movement.  The half-shaft was clunking against the diff and inside CV.  There is similar axial movement on both half-shafts

Moved the half-shaft to be against the outside CV and the clunk disappeared, only to return again a couple of weeks later as the shaft migrated back towards the inside CV.  There is similar axial movement on the other half-shaft, but is remains positioned near the outer CV and does not clunk.  The outside CV has the slip joint to provide the suspension travel movement.

The RealOEM diagram shows a clip that holds the half-shaft into the inside CV.  If may have come off?

- Is this a common problem with BMW cars?

- How hard is it to fix?