[rotorwrench]

He's talking about the sun gear ring plate & balk ring. The friction has to be right on the balk ring or it won't allow the pawl to engage the ring plate. It's not a bad idea to do a good internal inspection on these old units now and then. If the planetary is worn out, it can have catastrophic results when something breaks. Most of these units last really well under normal driving conditions but everything wears out eventually.