Before you said that I was gonna say it was the BJ in the upper control arm...still might be because what you describe sounds just like when one of mine went and I couldn't figure it out either. Whenever I'm checking ball joints I check them all...for example, if I had a bad UCA ball joint I would double check the lower ball joint and the tie rod end at the same time.

Also, aftermarket parts aren't necessarily bad, for example I bought my upper control arm (w/balljoint) for $81CDN + tax and have driven on it for a year and a half...bought my tie rod end for $26CDN + tax and have driven on that for 6 months. Now at Honda they wanted almost $300 for an upper control arm...and almost $100 for a tie rod end...ummm, no. When I can buy almost 4 parts for the price of one...which do you think I'm gonna choose. The thing is, I get my aftermarket stuff from 1-3 different places in town...always...it all depends on the aftermarket stuff you get, so far I've been lucky.

Now back to your problem...it sounds more like a ball joint problem than a spring problem...from how you describe it...but it's hard to tell without hearing it.

Hope my babbling helps...

Jason