Associate wtpart

Hi ,

In Windchill 10.0 M010, I am already created a WTPart inside Windchill. Now am creating a CAD Document with the same name of WTPart. But  when i check in the cad document with out use Auto Associate option.

But after check in the WTPart and CAD Documents are not associated. I read somewhere like if the names are same it will associate automatically.

Whether i have to set any Preference for that???

Thanks in advance..