97 Chevy 1500 truck auto C4 tranny puddle leak in rear

There may be a hole in the slip yoke end to prevent noise when the yoke plunges, if that is the case, there is usually an O-ring on the output shaft to prevent fluid from entering the yoke and leaking. Check if this o-ring is there. The coolant leak and the refrigerant leak should not be related. The coolant leak could be water pump, intake gasket, or heater pipe fitting. I don't know how far up front you are talking, could even be the radiator. Refrigerant could be leaking from service fitting(s), line, hose, or component.