[texwayne]

if you depress the clutch while still on the throttle the rapid release of pressure in the drive train when the clutch disengages will cause a loud "clunk". this only happens in lower gears where the engine RPMs are a lot different from the axle RPMs. in low gears your engine torque is multiplied quite a bit. the engine and transmission twist on their mounts. when you disengage the clutch without releasing the pressure, all the parts that twisted slam back into place. it's not a good thing.