What @Gordon Nichols said- the welds that hold the guide tube in place have been known to break loose, especially when using a heavier than stock pressure plate. And what @DannyP said about the fingers on the throwout bearing shaft- it's not unusual for those to break loose with heavier pressure plates as well. I've never seen/heard of the arm that attaches to the shaft (that the wing nut sits on) bend or break but anything is possible.
There are several places that sell versions of @Michael McKelvey's little tool (sorry Michael, I didn't mean to infer... oh, forget it!)