Rebuilt 904. Whirring. Dead?

Sounds to me like the front planet blew up.

DING! DING! I bet we got a winner there. The front planetary is directly attached to the output shaft and is locked stationary in reverse so a broken one would do all those things. In my 30 yrs. of rebuilding TF's I've never actually saw one break but I've heard they do. Good thinking j5. Have you saw that happen very often?