Is it the clutch or the transmission??

[Rb20_POWER]

So i've recently experienced a problem that happens intermittently with my rb20, i'm expecting that it has to do with the clutch or transmission. Hopefully someones has experienced or knows what might be going on so we could possibly single one out.

When I put the transmission in either first or reverse (which go in fine), at a stop, and slowly let out the clutch, there is a point where it makes an awful sound (rubbing, vibration, ?) and it only happens intermittently. I've noticed that starting uphill will cause the problem to happen more frequently. She shifts through the gears fine. Its only when I start disengaging the clutch pedal in first or reverse do I hear/ feel the vibration noise through the shifter. Never replaced the flywheel,clutch, pressure plate, pilot or throwout bearing and have taken it relatively easy on the transmission. Does it sound like it could be a synchro problem? throwout or pilot bearing? pressure plate? flywheel? Let me know guys, thanks!

[Joe]

pilot bushing, clutch chatter or throwout bearing.