I had a wobble on my rear z rod.

I made this little bushing to fix this issue. I printed 4 of it in different heights for variation to adjust the gap between the z rod and the top bearing (2x 0.6mm, 1x 1mm & 1x 2mm)

Print in ABS or at least PETG.

0.2mm Profile

You can change the height in your slicer for your own need.

Remove both screws above the rear z rod bearing. Go with a small pick or allen wrench from underneath the bearing and pusch it slowly out (left, right, left, right ;) be careful it pops out and will fly). Install for example the 1mm and pusch the bearing back. Check if the wobble is still there and adjust with other bushings if needed (for example a 0.5mm on top of the 1mm)