Andersen sliding patio door - height adjustment won't hold

[21golb]

I have a 1992 Andersen sliding door from my house to my deck.

Just recently noticed that the door doesn't align. It slides okay, but when "closed" there is about a quarter inch of separation at the bottom of the door between the door and the frame.

The door has two sets of adjustable rollers along the track. If you put a screwdriver into an adjustment hole on the bottom of the door and turn clockwise, it raises the rollers; turn counterclockwise and the rollers lower.

Except I can't get it to work.

One set of rollers, I can relatively easily turn clockwise, and the door raises and is visibly straight. But then let go of the screwdriver and the rollers and door revert to pre-adjustment setting. The other set of rollers I can't adjust at all.

Is there some trick I'm missing?

I'm sure it's not that expensive or difficult to order new rollers and put them in. But before I do that I want to make sure I'm not overlooking something that would account for my efforts not working.

[pushkins]

What you may have found is that the adjustment screw is not screwing into the wheel housing correctly or the thread is stripped, those doors can be heavy and if at some point the screw was all the way out with just a couple of threads in then striping is a common occurrence. Sometimes they get screwed all the way out and when you try to screw them in the screw misses the alignment hole and wedges itself elsewhere that does little to any adjustments.
The only way to check this is to remove the door and lay in on its edge and then you will be able to see the wheel housing clearly. If required that parts are pretty easy to find either at Anderson or any number of supply houses in any bigger city, the wheel housing should have a part number stamped on it.