Mazda b4000 new starter grinding

I have a 2003 mazda b4000 4.0,
5speed 2 wheel drive, I got a new
starter 2 bolt and I tryed everything
and it grinds every time . It has
worked for about a month also
having a slight grinding sound then
or now will not start . I tried shims
no go , is automatic starter
different then a standard
transmission starter could I have
got the ronge one , or if I sed ford
ranger same year and gave me
starter for that instead.  They
looked the same I compared them
also . Can it timing or a trick to line
it up but it's only two bolts?