cable bushing at transmission

[lifesave]

Hey all! i picked up another sho! its a 1990 mtx, shifter went limp when i took it for a drive and barely got it home, order new bushings from sho source and confirmed it was a cable shifter, replaced ft/back bushing at the shifter and was okay, replaced the same bushing at the tranny, installed and put in snap retainer, the cable end fit nicely but noticed that nothing would hold in from up and down motion, but okay . was out for a drive last night and sure enough it slipped off the top!! the retainer holds the bushing put the circular cable end is not secured from popping off.
SOOOO what am i missing here?? any advice or other owners have had this happen??