Sliding door slider wear?

[ronmidg]

Have a rattle from LHS when hitting potholes and prime suspect is sliding door. Has new seals 3 months ago and have adjusted after letting seals settle. Door rear corners are tight top and bottom, top front corner is tight, these three corners are all flush with bodywork. Bottom front corner is about 1mm loose with the lower slider bracket adjusted into the door as far as it will go, and the door is about 1mm proud of body here aswell. Pushing the door in by hand there is a hard knock from the greasy slider thing, it does not bottom on the seal. What should clearance in the slider be? I'm wondering if there is a repair that has the track misplaced as both front and rear wings on this side look like replacements.