i got the bell loose and the ujoint out. now, how do i tell if the u-joint is bad? it doesn't have any balls in it like i expected, and it's got about 1/16" slop back and forth between the caps in the axle side (not the brass flanged sides). it doesn't work as smooth as ball bearing models and i'm surprised this design works as well, but can someone tell me how to know if this thing is bad?

thanks.

Overland Blue, 1953 GMC 1/2T, 100-22, 228/1bbl, 4sp/4.10 6v, shortbed/fender side/5-window.