Capitol Sliding Window

I identified and purchased the worn and missing parts for my 1973 Capitol Large Sliding Window, including the rollers and top guides (87-006, 87-087).

I guess the rollers made some improvement but the new top guides seem to bind in the channel in some places and the windows wobbles in and out when in the closed position. It seems to bind against the center outer upright bar as the window passes by it which makes the window "rock" to the left and right unless you push from exactly the right spot. I was expecting a much smoother operation from these new parts but I feel there is still apparently something wrong.

I guess my question is the upper channel is bare metal and seems too wide for the window and guides. Is there something missing in that channel? There is a lot of clearance above the window in that channel and it seems things would work a lot better if the window rode higher on the bottom track, as if maybe the wheels on the bottom could be larger. Or, is this window just too worn out to actually run smoothly? Has the casement parts stretched out from age?

Thanks for the help. I checked the frame and it's almost perfectly square, no settling. If I just lift up on the window the slightest bit it moves back and forth smoothly, near perfect. Larger wheels would fix it. Any chance of a taller wheel? But I also noticed that you sell a snap-on track cover that would go on top of the bottom track, thus lifting the window about an eighth. Don't know if it's for my window exactly, but thought it might be worth a try. Even if it didn't snap in perfectly maybe the weight of the window would hold it in place.

Sliding window track cover 87-206?

Seems like it's worth a shot to me. I've got three of these sliders and I really like to open them a lot in the spring and fall but it's been such a chore. One is so raggedy that it cracked the glass trying to open it the first time this spring. Thanks so much for your help and advice!