I am having trouble getting my skylight vent arms to stay in the track.  They
    do not seem to have any lip on them to keep them in place.  Do I just bend
    the arms to keep them in there or do the "wheels" need to be replaced?

Sour as like the plastic ''runners" are broken or gone- common problem. only solution, short of fabrication, is replace the the flex arm assembly (which includes the "lift "mechanism, plus those plastic runners.  About $30 (on my website).

- Ron Salmon
  The Bus Depot, Inc.
  www. busdepot. com