Teac mech using in FD-2000

I have 2 FD-2000 3 1/2 floppy drives one I bought from someone that
sold his equipment but that mechanism just quit working all together,
wouldnt read or format.

  I used my first FD-2000 that has the later revision of the Teac mechanism
and I found 3 mods so I tried those on an *unaltered Teac*  this mechanism
most of the time works fine but at times it always seems to have a lot of
read/write errors and always reports bad tracks.  I tried these disks on my
working Teac in my other FD-2000 and it didnt have any errors and worked
just fine.

I thought I could learn something from this and its awesome I have at least
been able to use it but its just too error prone, which makes me thing I
havent really found all of the mods CMD had to make to the teac mechanism.

Does anyone here know of those Teac mods for the FD-2000?

If so I could send a jpeg image of the mods I have found to make the Teac
work.
I figured out the mod for sensing a disk change but if that isnt working
right would that cause lots of read/write errors etc?

Anyway I appreciate any pointers or suggestions, but for the most part it
kind of works at least, yay.

Again im referring to the Creative Micro Designs FD-2000 that is the
upgrade from the earlier 1581 3 1/2 that will format the usual smaller
capacity and it is capable of formatting High Density. (for those who dont
know this)  :)

Terry Raymond