upper rack off track

happened on right side of rack under warranty. Now, 4 months out of warranty, it happened on the left side. Front left "axle" / plastic wheel assembly disintegrated, leaving rack only supported by rear wheel. Replaced entire rack adjuster. Can be a little tricky how it latches onto rack - keep good track of where things went and/or keep one rack adjuster on rack (left or right) at all times to use as a guide.