I created a split zip archive using WinRar and 7-Zip.
WinRar creates
archive.zip archive.z01 archive.z02 ....
7-Zip creates
archive.zip.001 archive.zip.002 ...
With Total Commander I could enter(CTRL+PgDn) archive.zip (WinRar) and see the contents.
But I cannot enter in archive.zip.001 or any .xxx files.
Are there any differences between splitting with WinRar vs 7-Zip ?
There is definitely a difference.
ex.zip.001
is an .001 file in windows eyes and not a zip. Unless you have specifically registered the extension(s) it is unlikely that windows knows what it is (and apps that use the windows file type info to handle files)