Ok guys here is the deal. I searched for this answer and I get varying answers. Here is the problem. 95 Z28. Shifts fine manually 1 2 3 and overdrive. Once in overdrive it slips if pressure is applied. The ABS Inop light is on and the brake/abs light keeps flashing like there is a short. It still cruises in overdrive just cannot speed up fast. The ABS Inop light goes off and the other lights stop flashing and the tranny does not slip in overdrive anymore. It shifts fine and runs great in overdrive when these lights go off. Back to slipping when they come on. They go off randomly but are on more often. Please help?

 

Maybe the speed sensor on the tailshaft of the tranny has a bad connection.