1998 Chevy Astro front pulley (or balancer) grinding on tie

Suspension problem

Recently our 98 AWD Astro started making a terrible noise when backing out of our driveway. The sound starts when applying the brakes while in reverse. Sometimes it will continue when stopped, but go away once the brakes are released. This morning my wife was backing out and the noise started, so I was finally able to get a look under the van. There were sparks flying around and it looks like the tie rod is hitting either the lower pulley or the balancer. I wasn't going to poke my hands up in there to find out. What in the world can be causing this? And only in reverse? In 33 years of driving I've never even heard of such a thing! Please help!


NEVER MIND, IT'S THE IDLER ARMS.