Very common problem on these cars. Search around for the tips on how to replace the bushings, they are too stiff to press in with your fingers unassisted

New bushings make a huge difference in the feel of the gear shift. If your handle flops around like a dead fish instead of snapping into position, I would try bushings first.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech