Noisy / resonating x-axis  

Noisy / resonating x-axis

MK3S+

I've read a few posts about noisy and resonating printers. There seems to be a vast array of possible causes - almost as many diagnostic processes people have attempted. I'm here to ask a couple of basic questions about my specific issue and I'll keep the thread up to date with what I do and how (hopefully) I eventually solve it to help others in the same situation.

Printer is a self-build and had no immediate issues at all. In fact, I was somewhat surprised with how well it just worked (I assume my patience in the build made the difference). After a few months I noticed a noisy rattle sound, like a screw was loose and being vibrated by the mechanical vibration of one of the axis or motors.

It took me a while but I managed to find that by squeezing the x-axis tensioner assembly with my fingers (see below), the noise stopped.
I also noticed that it was worse in normal mode, but only a little better in quiet mode.

I realise that resonance issues are complex and by pushing on the assembly I dampen it and could be stopping whatever is resonating from doing so. However, it does seem like the sound is coming from the bearings.

So, my questions:

1. Would you go straight in and assume it's the bearings and attempt to repack with a good grease? If so, does anyone have any guide for the least trouble in dismantling ?
2. Are there anything other diagnostic steps anyone would suggest I try before tackling the disassembly?

Thanks!