Save as is changing parts in all Assemblies

Hello All,

A new problem (for me that is):

I am in an assembly and wanted to lengthen one of the parts ONLY is that specific assembly. I saved the part as a new name and made the change on the new part. All was fine and the current assembly now show this new longer part. BUT ALL other assemblies which used that old part, now show the new part. I have a mess on my hands please can someone help. I can't even go back and replace the older good part any more.

Thank you

Sammy

SolidworksAssemblies