the root cause is a old design that is prone to developing excessive on-center play.

What happens is the follower gets a little play,then normal vibration starts wearing a 'low spot' in the sector gear (which is ground slightly oval so it is 'tight' on center, and has more play off center) Once the 'low spot' develops, it is impossible to remove the on-center play without the gear binding just off-center. Low cost (cheap) rebuild is really just seals and not the real wearing parts.

Prevention means keeping the follower 'properly' adjusted all the time to minimize development of the 'low-spot'. If the follower is tightened properly? , and enough turnsof the steering wheel are made, the rest of the sector gear wears at the same rate as the on-center portion- at least that's the 'technical explanation' MBZ has published.

Another sh#$%$ peice of 'German engineering' in my opinion--just like the wiring harnesses that self destruct and transmissions that fail regularly, and......

The more I drive my 1994 Q45a (active suspension) the more I appreciate the high quality of that car--and the less respect I have for MBZ. My 94 sl-600 is a peice of sh#$ by comparison. I am in the middle of a tranny rebuild @84K miles because the oil pump ate itself up--regular fluid and filter changes- Indy shops say they see it all the time with MBZ. Still fighting the flakey (get the pun) wiring insulation all over and ETA's. Another MBZ crappy part.