You have to mount the upper toolhead screws to a down position on the linear axis. Then you should be able to adjust the proximity sensor.
There is somewhere a support article about but this is it.
Please let me know what this plastic thing with sensor cost, thx)
While researching issues surrounding bed leveling I came across the note in the troubleshooting guide about confirming or setting the height for the inductive bed height sensor.
So removed my printhead and noticed that the sensor seemed to be tilted toward the back of the printhead enclosure and decided that it must need to be adjusted. I tried to back out the cap head screw that would allow the sensor to be adjusted and found that the screw just turned while making a ratcheting sound. After taking the side cover off I discovered that the rosan fitting in the sensor mount (also fan duct) had cracked the plastic it was inserted into. And so it came out in pieces.
After removing the other side cover and gaining access to the circuit board I unplugged the sensor and removed it completely. I had already printed out a mount for the IR sensor as a test, so I cut that down to retain only the fan duct and reinstalled that, leaving the sensor out.
I got a small pair of pliers and while holding the rosan fitting I removed the screw and discovered that there seemed to be some corrosion between the screw and the brass rosan fitting. It’s either that or somebody used Loktite when they assembled the sensor into the printhead.
I have now done a 25 point bed level and am using a glass bed from Amazon and my prints have never been this good. Never.
I am now reading through all the posts I can regarding print accuracy and proper setup because I’ve discovered other things like confirming the extruder calibration…these are things I never knew about and I’m pretty sure I never saw them in the manual.
I have a ticket in to request info on a replacement inductive sensor and will post back on availability and cost if there is any.
Instead of getting a new inductive sensor, you may want to consider replacing it was with a capacitive sensor, then you can do auto-bed level calibration with the glass bed. The modification is quite minor; I am in the process of doing it on mine right now.