Yup sounds like a rack job in your future. At least on a diesel 210 those never came with 4matic, so it's right out in the open and looks to be a totally straightforward swap.

The rack on our 2008 ML went out with the same failure mode. We ended up having an indy replace it because it required dropping the transfer case to get it out. Something I didn't want to do on my back with the beast on stands.

__________________
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