Ever since i had my driver side axle replaced, i developed a knock under acceleration. Here recently (about 15k mi later), the knock has become horrible and is noticable when you have your foot off of the clutch, or when you accelerate. Also, sometimes at start up, the clutch pedal will be very stiff, and after the car starts, you can feel a harsh vibration in the clutch pedal and you cant engage any of the gears. I have a suspicion that i have a bad pressure plate. But i have thought it could be from not having tranny fluid. It is a sealed transmission, but i have noticed that around the drive axles there is fluid. And also, there is fluid underneath the trans itself. Very clear, not like oil. The knock could be from a combination of the two. Any thoughts or suggestions would be greatly appreciated.