Taz 3 Bearing Sliding out

So I just got a used taz 3 and the solid polymer bearing on the bottom right size keeps sliding down and popping off the double bearing holder when moving the z axis. How do I fix this? Kind of new to 3d printing.

The bearing holder may be cracked or worn. The ultimate way to fix it is to print a new one, probably the newer Taz 5 style which will fit and resolve that issue. That being said, you can fix it temporarily to get you operational. To do so, pop the bearing out, while still on the rod, wrap it in tape until it fits in the holder snugly but doesn’t drag on the rod (2-3 layers should do the trick) then shove it back in.