Way back when . . . had a tick noise on rare occasion on rear Phil hub on our custom Colin Laing tandem (mid-1980s).
Our solution was: coast . . . pedal one revolution BACKwards. Noise ceased.
Have put big miles on Phil hubs on our previous tandems: our Assenmacher: 64,000 miles; Colin Laing 56,000 miles; custom Co-Motion 57,000 miles.
A great product and service.
Pedal on TWOgether!
Rudy and Kay/zonatandem