Sorry to hear about the multiple failures. I hate it when all the cars break at once. The Landcruiser was down with a bad radiator a few weeks ago and I get in my daughter's 84SD to drive to the parts store and the ignition switch failed with the steering wheel locked. I work on mine in the street, so I feel your pain.
Do you have reverse? If you don't have reverse, it's not the B2 piston (I think). If you do have reverse, you may be able to drive it backwards in the middle of the night to a location where you could work on it and replace the B2 piston. If it's not the B2 it could be a broken flex disc, broken axle, spline backed out of the yoke on the back of the transmission or broken ears on the front shaft.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13