Jr. Y Axis Bearing replacements?

Are the bearings loose inside the bed carriage, or do they just have a lot of play against the 10mm rods?

If it's just against the rods, and there's no friction issues inside the bearings, you can probably tighten that up.

First, loosen the screws that hold the glass on the bed and remove the glass. Then remove the screws that hold the bed carriage onto the assembly. You can then loosen the clips that hold the Y assembly cover down to get access to the rods.

There are two screws at the front and two at the back that mount the rods. Loosen all four, then slide the carriage all the way forward. Gently pry the rods outward while tightening the back screws, then slide the carriage to the back. Repeat the prying and tightening.

With any luck that'll tweak the rods just enough to eliminate any side-to-side play in your bed.