My clutch seems to be adjusting itsself so that free play at the top is increasing. If the clutch were wearing out, wouldn't the opposite be true? It's got to where it won't always fully disengage when I romp down. I have a 10 3/4" clutch and 4 speed transmission in a 1/2 ton '49 Chevy w/'58 235 engine. What would cause this?