Transmission bad or b2
 

Hi all
Last night with out warning my 1992 w124 300d
450000 miles on the engine 270000 on transmission suddenly would not engage in drive. Nothing car rolled backwards, reverse engaged normally plenty of tranny fluid, the fluid appears clean with no odor.what could this be? As my ideas and tests welcome.
Everyone ave a nice holiday.
Ken
I had the transmission serviced about 50000 ago.

Not sure what transmission you have, but for a 722.3 this would indicate a b2 failure, yes.
No forward gears, but with a reverse gear still working is the typical symptoms for this failure.
Of course, it's possible your shifter lever bushings have gone bad too? Not likely, but something to check first.