> wrote in message
oups.com...
At any rate, what would cause
> the bolts to work loose besides someone loosening them? Anybody got
> any recommendations on what I should tell the mechanic?

Every ball joint I ever replaced had a cotter pin to hold the nut in place.

The replacement joint itself is normally held in place by three bolts, which
replace the original rivets.

$550 for ball joints sounds high...REALLY high.

I don't know who is humping you, but I would suspect that someone is, or
has.