I have searched the forums and couldn't find anyone with a similar problem that I just started experiencing. I have a 2001 S60 T5 with a manual transmission with about 180k miles. The car has been perfect and I just preformed a tune-up, but have started to notice a jerking when pushing in the clutch and when I engage a new gear (the wife thought it was my driving). I also noticed that while at a light and I press on the clutch, the car will drop very slightly in RPMs and shakes a little but for only a split second.
Any ideas?

check all the motor mounts