If your bearing keeps wearing out quick it can only be a few things. A: your input bearing retainer is warped and needs replaced B: your cable is too tight and keeps constant pressure on the tob which leads to premature failure, can also lead to premature pressure plate fingers failure. C: You have **** luck with tob and need to go buy a ford one.
Any of the above could be possible... or a combo of all three. Either way, your pulling the trans again. Take a close look at how ur cable is routed now and if it gets pinched anywhere. Then look at ur bearing retainer and put a straight edge on it to see if its warped or has grooves in it. Lastly, go buy an oem replacement...if they can go 100+k in a stock car, no reason for them to die on u.