just got a 85 invader 12 0/2 7 0 was stra n d e d on lake ran fine a l l day finished up tubing boat would shift butt wo u l d n.t engage checked today removed cover shifter moves levers in back but used fingers to Pop into position could this ne e d a n e w cable. and could it mea nmore oil in the drive.please help new to boating female not trying to be took by mechanic