(Claim 1) 1. An earth di_giiig replaceable tooth cap retainer forsecuri-ii_ a cap havin.- aligned side openings upon a base having a cross bore, coinprising: a sprin- steel elon- gated pin bent intermediate -.ts ends forming a wide angle V to permit resilient yielding of the pin upon mcvement of the legs thereof toward endwi e a ignment, a wed.-e surface fom-ied on each end of the pin for engaging the replaceable tooth cap within said side open- in,,s perinitting springin._ of the pin within the adapter bore by endwise iiisertion, and a shoulder on the pin at the base of the wedge surface for retaining the pin within the adapter bore against accidental removal, said pin i-es,'Iie,-_tly urgir_g the cap oil said base when the pin is sprung in the cross bore and cap side openings with the ceiitral pin portion engaging said bore and the ends of the pin en.-a.-ing said cap.