Muon spin depolarization has been studied in moderately concentrated AgMn and AuFe alloys from the freezing temperature T-g up to 300 K. The muon depolarization function can be analyzed to show that the temperature dependence of the strongly nonexponential form of the local spin autocorrelation function in these canonical alloys is similar to that observed in numerical simulations on Ising spin glasses. The dynamic behavior above T-g appears to be an intrinsic precursor to spin glass freezing