A method includes receiving a first shaft speed, measuring a parameter indicative of a PTO shaft speed, determining a PTO shaft acceleration by monitoring the parameter indicative of the PTO shaft speed over time, determining, via a plurality of estimators, a plurality of normalized PTO clutch gear ratios, wherein each of the plurality of estimators determines one of the plurality of normalized PTO clutch gear ratios based, at least in part, on the first shaft speed, the PTO shaft speed, and one of a plurality of known PTO transmission gear ratio options, and selecting one of the plurality of estimators, when the PTO shaft acceleration drops below a threshold value, wherein the normalized PTO clutch gear ratio determined by the selected estimator is about 1.