How do you know when the clutch is wearing out? How do you know when the synchronizers in the transmission are going out? I have occasional trouble with grinding gears while shifting. Clutch can be thrown all the way to the floor so its not that. It happens most often when shifting up or down...

My truck is a 1995 and my synchronizers are going out. I am wondering if you can take them out and run with out them. It is a E4OD manual, and if I can't run without them how much does it cost for new ones? Also can you drop the trans without pulling the engine?