I have a 50 AD with 3 on the three. Just recently my gear shift locking up on me. When it does I have to manipulate the shift levers at the control box by hand to un-lock it. Basically putting back into neutral. I made all the adjustments the manuals show but it still locks up. How ever I did notice the coil spring in the control box has a piece of the coil at the 1st & rev lever that is sticking straight out. Could that be the problem? Any Ideals? Are replacement springs available anywhere.