i have a knocking that i can feel through the floor pan, gets faster as you speed up and slower as you slow down, so its deffinatly speed related. if i dip the clutch it dosnt make a difference. i have changed the gear box and driveshafts to no avail. on the day the knocking started id had the rear tyre changed. knocking started off fairly quiet.. but has got louder over time. suggestions? i am STUMPED and its starting to get expensive