Post by alexthepunk on Jul 13, 2015 15:27:26 GMT -5
Check for loose wires. The y-motors run off of a y-adapter wiring harness, which means they are both getting the same signal at the same time.
If nothing is loose, there may be a bad component inside of the y-motor itself. Try swapping the motor for one of your extruder motors and see if it fixes the problem. If it does, you have a bad motor. If it doesn't fix the problem, there is a loose connection somewhere.