A carrier for a window sash having an actuatable friction adjuster. The friction adjuster has a carrier interface that interacts with a mating friction adjuster interface of the carrier such that the actuation of the friction adjuster by rotating it within an oblong slot in the carrier causes the carrier interface to interact with the friction adjuster interface and forces a rear portion of the friction adjuster into progressively increasing frictional contact with an adjacent portion of a window frame sash channel.