X axis really tight on one direction (2 replies)

All of the sudden I noticed my x axis is incredibly difficult to move in one direction. In the other direction, it is completely fine.

I have a mendelmax, and use 4 igus bushings for my carriage on 8mm hardened rods.

This literally started happening today.

Anyone have any ideas?

Also, can I use any lubrication on the igus bushings?

Thanks