I have a file located in "My Documents" named "Standard Parts". These parts are used on numerous assemblies. When i correct the placement of these parts and go into a different assembly with the same "Standard Parts", there are mate errors or/and they have moved.
Please see attached. The blue pins are from my "Standard Parts" and are floating in space.
Is the same chassis assembly used on multiple trailers? If you move the pins around within the chassis assembly they will stay in that same place everywhere that chassis is used, unless you leave them unconstrained in the chassis and make the chassis flexible in the trailer.
I would recommend putting the pins in the trailer assembly rather than in the chassis assembly. Then you have different instances of the pin assemblies in each trailer and changing locations/mates in one should have no effect on locations/mates in the other.