My Murray (16.5 HP OHV 42" Automatic Drive) (Model# 42576X92B) (S/N 7431603501F00626) quit moving in rev or fwd. The drive belt is on and pulley on top of transaxle is spinning. (The transaxle is a TUFF TORQ K46D P/N 1001017) It was low on oil so I added about 1/4 cup of 30W oil. What can I try or look at. Is the keystock on the axle to wheel important which I have not checked yet?:frown: