I bought them because I thought AC Delco was the best parts manufacturer. As soon as I started filling one with lube it started leaking out the side. No problem, I'll just buy another one and send it back. A few weeks later I replaced the bushings on the levers and the other side of the rubber was no longer lubricated and cracked. Apparently they've been in storage for years and haven't been exchanged because the rubber shouldn't tear like that for a month. If you're looking to buy a ball joint and know for sure it's going to work hard, don't buy this one.