That sounds like a fault with the actual clutch/pressure plate/thrust bearing, rather than a fault with the cable/actuator mate, sorry

Was it all brand new on install, did you put a full new clutch kit on?? You did use the flywheel from the car the gearbox came off yes??
A badly installed clutch can cause the friction part of the clutch to shear from the centre, drive part, this causes a crunchy, grinding noise when you press the clutch in