[quote]ORIGINAL: pilotwings119

and TWICE a rock got stuck in one of the back wheels

When you get rocks stuck in the wheels like that, it breaks the webbing where it connects to the hub. If you break a couple of those, your wheel will start wobbling like a bent axle.
I think a bit of CA would fix them. I plan on trying on a couple of sets of mine that have suffered from that. I'm just waiting for winter to end. and waiting. and waiting...still....waiting........