I've now handled four Caldercraft "Fineline" stainless M4 propshafts - one 7", one 5" and two 4". The 7" one is fine, but the other three all exhibit run-out at one or both ends. The amount of run-out is not consistent between shafts or at each end of the same shaft, but it's clearly visible when the shaft is rotated by hand in the tube. By the time the coupling adaptor's gone on, the total run-out at the motor end of the coupling is ample to create vibration and noise.
I've established beyond any doubt that this is not due to damage in transit: they were definitely made/threaded wonky. Have I just been very unlucky indeed, or is this par for the course with these shafts?
And if I want a simple M4 propshaft assembly (say 4" or 5"), where can I buy a decent one online? Anybody know what
this range is like?