I found the answer. After numerous calls and net searches...I can't find these anywhere. So I decided to make them.
Home depot sells Tub and Shower replacement hardware (at least in my area). This consists one pair 22mm and one pair 19mm diameter nylon wheels with bearings and set screws. Hopefully, the bearings will last because after all, these are for the shower. Anyway, since the smaller wheel is just a touch too big, and there is no way to make it smaller and nearly round, I decided to just trim the edges and let the nylon act as a slid and the inner bearing take some of the turning force. Just a few mm ground off and squaring up the edge and it works perfectly. Used som locktite on the set screw after drilling out the OEM pin.
a few more pics:
the nylon wheel does not actually turn in the guids, it slides (pretty much like the old worn wheel did, probably for years)
Don't take more than necessary off the nylon wheel because you will expose the bearings...
If you don't want to mess around, you could spend 114$ for the non-powered new mechanism....
