There are a couple of things to look for on the trays:

1) Is the sector gear cracked, loose, screw gone, screw loose, screw bent? The check is to remove the back cover and watch it lift. If the sector gear hits the right arm of the tray before it reaches height, that's a good place to start.
2) If the sector gear is OK, and it's still hitting the right arm, put a little extra bend in the lift plate screwed to the shaft. It starts out with a Z-bent 90 degrees on each bend. At the longer end, change that bend to 88 degrees. It will buy you an extra 6mm of lift.
3) Does the cassette latch? The delrin latches do eventually wear out. 30 seconds with a match can tighten up that latch for you. It's a good idea to stop warming it if it bursts into flames.
4) Is the tray mylar in good shape? I've seen quite a few mangled mylars lately. Most of the time I'll try to manufacture something on the spot, but this one is pretty rigid, and hard to substitute for.

=^..^=