This old Chrysler(1966?) runs like it will do so forever, but has trouble shifting into reverse when it is cold. Shifts at too high RPM and the noise fron the lower unit can make you shudder. After a short run shifting is normal and takes place before the engine revs up. All adjustments on the cables and linkages are secure. The shifting is all mechanical, of course, and I can't see how engine temperature can be affect it. I haven't opened the box. According to a patent notice sticker it was made for Chrysler by Morse. Any clues will be most appreciated.