'93 LX with transmission woes

[Terrasque]

Car info:
'93 lx 2.3l hatchback
Bone Stock
160k.

My Mustang has recently and for the first time started giving me trouble. It started with getting stuck in fourth gear. I was driving down the highway and downshifting as I was an off ramp. It would simply not come out of gear. I depressed the clutch again and my forcefully pushed on the stick and with a grinding noise and feeling (think shifting with the clutch pedal half way depressed) it came out of gear. I thought this was a fluke as nothing similar happened for over a month. This week similar things have started happening.

As I shift into fourth, and only in fourth gear, with the clutch pedal on the floor the gears grind as if the pedal is only half depressed. Also, when shifting from fourth to any other gear it will often get stuck as mentioned before. I've found that if I try to shift out of fourth and then place it back into fourth and out again that I can get out gear but there is a definite grind at the first attempt.

Does anyone know what would cause this to happen? I've searched some posts and think it may have something to do with the synchros but honestly have no idea how they (it) mechanically work. Any help is greatly appreciated.

Michael Lesko