Still no go

Have tried suggestions on solving tranny/driveshaft problem in '83 300D . Output shaft has backed off far enough to disengage spline . No evidence of output flange movement . I have been able to re-engage output shaft to spline and adjust output flange to reduce play in shaft ,however there is still enough play in the output shaft for it to disengage again by the time the car moved 1/4 mile. It seems to me as though the carrier bearing has collapsed allowing the output shatf too much play between the tranny and the output flange . Assuming that the output shaft hasn't shrunk in our unseasonably warm Newfoundland weather ,and with no structural damage evident,I'm thinking the problem may be with the carrier bearing .
Any thoughts or suggestions would be greatly appreciated .