Make sure the ball on the clutch fork arm that holds the throwout bearing is all the way in the socket. There is a little two-armed retaining spring that it must push past to seat all the way. If it isn't all the way in there, the throwout bearing will do some funny stuff. Ask me how I know.
Sascha Steinway TLCA # 20217
1977 FJ40 "Ripper" (because it shreads!)
1988 FJ62 "Dino" OME, now in the hands of my daughter
2013 F-150 "Black Ops"