X axis troubleshooting Ender 3V2 Neo

Hello all
First off I have some questions in general on how stepper motors count turns or report position to the mainboard ?

Now to the root of the problem

my x axis ive had issues with it since about 3 weeks ago it made grinding noises when moving no big deal it completed the print no problem ( my guess is forgein debris in the belt drive line)

Since then it has failed positioning about 5 mm off the bed at 0 and about 15 mm short at 220

got it back working checked tension on the belt lost the screwcap and thought I had a homebrew tensioner using a 4 mm 16 mm long bolt and it put tension on and I figured it was good
then x axis is skewed further and further to the right as it went up

rehomed printer and it failed rebooted and tried moving axis a bit left and right and as it homed again after i had it moving smooth it was saying 150mm and it was maybe 40

pulled the entire x axis apart tensioner off to check and visually inspected rail and no debris found

I moved it manually with no power and felt clicking/ catching but could not determine if that was the carriage for hot end or the stepper motor and pulled the wheels off and checked the bearings and no issues found

I have not re assembled adn re tested yet as my eyes are crossing

anything else I should look at as I re assemble ?

Do I need to bite the big one and just replace everything but the hot end carriage and rail

For reference this printer was new in Febuary