When I first installed my AP twin fork tail wheel , I did not like the cheap ass bearings that came with the wheel , so I bought the "upgraded" bearings from Spruce and installed them . All seemed well with the World !
During the current annual I decided to remove the entire tail wheel assembly and have the rod , fork and bolster fitting powder coated ...got tired of painting the assembly . When I removed the wheel , one bearing was almost frozen and the other showed indications that is was going to fail also...you could feel the bearings rubbing inside the housing . The thru bolt also showed wear on the same side as the failed bearing and the impending bearing was beginning to show wear on the bolt . I have new bearings and plan to install them in a new wheel . Not sure what caused the bearings to fail , but it might have been operator error ? I did not use a press to install them . Any case the newly installed/powder coated unit should look great ! 
I'll post pics of the final assembly .Just because the wheel spins freely does not mean the bearings are OK . >:(
RB
The replacement bearings I got from Spruce came from Japan and float like butter ! 
You are right about the loads on these bearings Dan . They take a beating ! Based upon what I found during this annual I will pull the wheel every annual and at least "spin" the bearings and look at the thru bolt as to condition . A bearing failure on TO or landing would cause me to ship my pants ! 
No BOOM , just clean drawers ! 
BOOM !
