I recently installed the outdrive on my 1978 Century and thought all went well. However, when I put the boat in gear and manually turn the prop, the prop will stop one direction (when engaged by the engine) and will "click" when rotated the other way. The sound is coming from the intermediate shift shaft from the lower unit. When I rotate the prop, I can feel tension on the shift shaft as it tries to rotate with the prop (but is contrained by the horeshoe collar mounted on the lower end of the bell housing). I don't recall ever hearing this noise before. Did I do something wrong? It is possible that the shift shaft may not have been completely in the forward position (forward gear) upon install, but it is defintely seated in the horseshoe collar of the bell housing. I have been told that the noise emanates from the gears in the outdrive not being fully engaged and that the sound should dissipate under power. When in neutral, the prop spins freely with no noise in both directions. Please advise. I do not want to start the engine until I have a better understanding of what is happening. Thanks.