What would cause a manual transmission car to shake and shutter when letting out the clutch?

 

It's usually a sign of a worn or weak clutch. Could be clutch disc, pressure plate, throwout bearing, or worst case a warped flywheel.

If it just started, I'd lean toward a weak pressure plate. Either way, start saving your money for a clutch job.

 

Bent or warped clutch disc. Hot spots on the flywheel or pressure plate, sticking damper springs on the disc. oil or fluids on the disc, something like that.

 

Clutch chatter and is usually more of an annoyance then a problem in most cases.

 

One other thing to check (and thought about this in church this morning when I shoulda been thinking about Eucharist )- check the transmission and engine mounts. If it's loose or broken, it'll cause the shudder too.

Is pedal freeplay within specs? you want about an inch of free pedal travel before you feel resistance in the clutch linkage.

 

true. your clutch disc can have lots of "meat" left on it, but if your flywheel is covered in hotspots- you'll get a chatter.

you can remove the flywheel and have it machined to resolve the issue.

 

I would check freeplay as mentioned above!!

 

Have a look at the rear end mountings while you are under the car checking the engine/trans mounts.