Remembering back, it may have not been the planetary itself that was responsible for the whine but wear against the case. It had what looked like a machined recess in the back of the planetary. I didn’t think much about it until I ran out of ideas as to why I couldn’t get my overall end play into spec. Then I took a closer look at the planetary and compared it to a new one which did not have a machined recess, and then realized the recess was from wear against the back case wall. With a new planetary my overall end play fell into spec. So, I’m not sure if the whine was from planetary gear wear or excessive end play.
I’ve only built the one TF so I’m definitely a novice - but it’s been working just fine since.
