I would assume it was this one,

This issue is becoming more common.
Bad 722.xxx-transmission output flange spinning on shaft

http://www.peachparts.com/shopforum/diesel-discussion/301813-transmission-problem-fix.html

http://www.peachparts.com/shopforum/mercedes-parts-reference-library/301849-output-flange-722-xxx-transmission.html

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