What transmission number do I have in '09 E350 4matic Wagon?
Standard E350s had 722.9 7-Speed Auto Boxes but yours is a 4Matic which didn't come with the 722.9 until the W212.
Fluid should be changed every 40K. 100K is too much between fluid changes.
For removal of doubt, every owner should have a copy of this extensive booklet.
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