loud single click in and out of coasting on Sturmey Archer AW hub?

I built up a new wheel with AW hub of unknown history; it needed new
oil and grease so I rebuilt the hub and laced up the wheel. When I
stop or start pedaling it makes a very loud distinct click (in
addition to the normal typical ticking of the pawls when coasting, and
the engagement of the pawls when you start to pedal again.) Have taken
it back apart again but don't see anything obvious, except that it is
difficult to get bearings adjusted correctly without too much play at
the wheel. This is my 6th or 7th AW hub and I have had much better
success in the past. Any advice greatly appreciated.
Cheers!