I do think you probably have the lower end helicomatic hubs on that Trek. They have suffered more failures due to small ball bearings and gaps at the cone that allow grit in to help them self destruct. I do have a few of these that are undamaged and seem just fine with light usage and periodic cleaning.
The higher end 700 helicomatics were found on some Treks and have some differences as pointed out by JohnDThompson in this post,
Maillard Helicomatic hub question
The labyrinth seals, bigger ball bearings, and better cones make them much better.
The 6 speed helicomatic freewheels I have work pretty well with Shimano indexed shifters as well.