1980 cobalt 260 MC-1 drive. Last weekend drive would trim up ok. But would not go down. The pump motor was running, didnt sound strained or anything. It would trim down when I throttled the engine up. When I got the boat home I checked everything visually and everything looked ok. I checked the nuts that hold the rams on the lower unit just to be sure I didnt over tighten them, since i had just put the drive back on a few days earlier. Now in the garage the drive trims up and down just fine. Any ideas????