hello, so i have a 1972 omc 120 sterndrive, with electric shift. at the end of last year it wouldnt go into gear either forward or reverse. took it to my mechanic and he checked for power in the wires etc. and thought it was a broken clutch spring, it was cheaper to order a rebult lower end that was bench tested to be in working order. he put the new lower end on and still nothing, engine runs fine and will idle all day, but no shift? any ideas on what it could be?