My Ion went in for annual inspection yesterday, and it failed (from a very trusted and reputable shop) because of play in the right front ball joint. Actually, not the ball joint itself, but where it fits in to the socket on the steering knuckle. (When the mechanic works the joint with a pry bar, there is some movement.) So I am in the process of replacing both steering knuckles. I have them removed, and nothing is broken or obviously deformed, but the socket/ball joint stem fit isn't really tight, even with the pinch bolt torqued tight.

So in researching purchasing replacements, I found a phenomenon that I can't explain. The two knuckles, left and right, look almost identical, although mirror images. But when you check the prices (depending on the manufacturer and vendor), the right knuckle is $50 to $80 more than the left knuckle. Does anyone have an explanation of why this would be? I don't have an objection to the price difference because it seems to be across the board, but was curious as to why.

 

I have found that the price difference is usually demand driven.

 

So the cone in the knuckle is distorted and a new stud (ball joint) is loose in it?
Knuckles are not interchangeable.

 

I realize that knuckles are not interchangeable. I had to replace the right one to pass inspection, but I believe in replacing both sides if one goes bad in most cases involving suspension/drive train. I can't tell by visual inspection, but apparently the socket for the ball joint stud is wallowed out some, allowing the stud to 'pivot' along the vertical axis at the pinch bolt. I replaced the ball joints themselves last year after slight looseness was detected during inspection, but was deemed to be still 'within limits'.