It should be normal to expect certain running changes. Nothing major, but certain changes are always being done on production lines, not on a yearly basis, but on a serial number range basis. Might be something as simple a different length bolt or a different filter element.
The old way of making annual or year/model changes only happens when major changes mean a new subseries, IE going from the BX 60 series to the new BX 70 series. Or from the BX24 to the BX25. Or from a tier 3 to a tier 4 compliant tractor.
Occasionally you will also get medium changes, which means that a suffix might be added to a model number, such as is the case with the BX25 verses the BX25D
Which it is always wise to have not only the model number in its entirety but also the serial number.
David
