Just got to the auto homing step and electronics look good but when I auto home it started making some straining/grinding noises when it was raising the bed. I noticed when I move z-axis manually from the LCD usually only the left side coupler will turn and the bed starts to go crooked, then the right side will turn a bit and level out some. Should I go back to reinstalling the whole bed or is there a quick adjustment to be made here? I turned the couplers by hand a few times and tried retightening them so feel like it is all probably out of whack now. Any advice appreciated.