Prop shaft noise

[Bob Culver]

A Seven feature. Metal to metal. Movement can occur in the small ball joint below and/or in the large sphere captured by the adjustable serrated ring. Often the ring is at the end of thread so no adjustmnet remaining. Yours may have a little left. (By dismantling, the face of the main containing body can be turned/filed back to give more adjustment. A dirty job, mostly from under, and the prop flange has to be removed, not always simple).Wear is uneven and care is necessary that with the two lock bolts tight, can move through full rear spring range including rebound without binding, with associated risk of fractures. Heavy grease helps. Most live with some degree of knock, more or less unavoidable when worn. Frequently settle out of square as yours and adj may worsen but no matter. I have seen springs fitted to pursuade square.  When binding cannot easily rotate slightly .

Are there any simple remedies? can nylon or somesuch be trapped somehow? (Took about 20 mins to complete!)