So I have a Haas SL-30 with a Kitagawa B210 3 jaw chuck. Just in the last few days for some reason it won't hold parts true to centerline anymore. There were no crashes or anything but it is being remounted after using a 5C collet for a while.

I mount the chuck and put a dial indicator on the OD of the chuck and it runs about 0.0004 TIR. The face is roughly about the same ~0.0004 TIR.. So I assume it's mounted properly, but when I try to hold a round bar it never clamps on dead on and i cannot use a dead blow hammer to adjust pieces into concentricity like I used to be able to. It's almost like 1 jaw has gone out. I've verifed many times that the jaws are clean and that there is no metal shavings caught anywhere in the jaws or the master jaws where the jaws mount on top of.

Since the OD and face of the chuck appear to be aligned correctly does this seem like the master jaws have gone bad? I'm trying to pinpoint what is going on here but cannot - i've disassembled the whole thing and cleaned it up thoroughly and still it's always out .007" TIR on parts in the jaws (right at the jaws)

any suggestions?

cheers!
Paul