Upper door frame of Andersen door

Question

My andersen sliding door on the bottom has a single raised "rail" for the rollers to slot over. But the upper doesn't. It looks like the upper rollers should roll in a groove. What is the deal?

Paul · Accepted Answer

Andersen just has a plain u-channel at the top for the door to slip into. The roller just rides in the channel to give the door tension so it won't jump the track.