Ford Aerostar Sliding Door Problem

I've got an Aerostar that has developed a problem with the sliding door. A couple weeks ago, I went to open it and when I pulled the
handle, the entire upper slide mechanism came out of the track. I pushed it back into place, but now every time you open the door, if you're not pushing against it, it comes out. I've looked at the upper and lower slides and neither appears to be bent, but the upper slide is rubbing along the bottom of the track instead of fully engaging into the track itself. Any suggestions on how to fix this? I was going to add a few washers between the upper bolts and the slide mechanism to raise it, but that might make it a bit wobbly.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.