I have a 2003 Trophy 2359 with a 5.0 Merc alpha gen2. Took the boat out this weekend, I started boat before lowering the outdrive(heard a strange sound, and lowered it immediately, drive was under water the whole time). Backed away from the dock in reverse successully, shifted into forward but only heard clicking and no engagement on the gears. retried many times with no success. Shifter/throttle felt same as always and thought I saw decent shift cable movement. Came home and dropped the lower unit and found that I could engage both forward and reverse by manually moving shift lever, I re-attached lower unit and tried re-adjusting shift cable according to the manaul, this changed nothing. I removed the shift cables and tested the one going to the drive and found I could engage forward by manually pushing all the way forward(this cable is only a year old as I replaced when I pulled of the stern drive last year). The shift cable going to the throttle controls was rough on the last half inch to inch, I manually pushed and pulled and put a bit of grease on threads which loosened it up. I found less than a half inch of play and was getting 3 1/8 inch travel which is what I thought was normal. No change after re-attaching the cables according to manual. I tried turning the barrel out an extra half inch on remote shift cable. This seemed to fix the problem, but when I reattached the spring loaded shift assist the problem returns. Right now I have left the shift assist off and am getting functionaly shifting but occasionally the boat does not shift back to neutral requiring a re-attempt to neutral. I know this is long winded, but I feel like I am out of options, what should I try next? Do I need to replace the almost 10 year old shift cables or shift plate? Is there anything else I can try? Thanks for the help.