Update:
So i took the machine mostly apart.
It is really dirty. I don't know what the pre-owners did with it, but dried up coolant is basically everywhere. Its yukky. It takes a lot of time to clean everything.
Linear guide rails on the Z Axis -> Scrap ( 2 out of 5 blocks are wiggling in the Rail) The rail is some special THK rail and is only sold as a set by Mazak. I requested a counter offer from a THK dealer... even more expensive.
The Y axis box ways are done. The lubrication system malfunctioned and the way wipers failed over the years. Already brought it in for regrinding. After that it needs to be scraped, which i am able to do. I lack a lot of experience in scrapping but its a "simple" box way and no dove tail ways.
Same goes basically for the X axis. Lube system got plugged up by failing way wipers and even the hardened ways got damaged. -> Regrinding.
Ballscrews:
Z Axis ballscrew is in good condition, but has no preload anymore.
X Axis ballscrew is in good condition, and still has preload.
Y Axis ballscrew feels a little bit crunchy... the balls need the be replaced and checked again.
Milling spindle:
The taper is shot and needs to be reground. I assume the bearings are also in no good condition. This repair also needs the be done professionally.
The good news:
I fixed my temporary encoder capacitor solution with a proper super cap. I even upgraded it to a 1.5F
