I bought a pre-made swivel hub from minisport a couple of months ago. The one that comes prefitted with ball joints and apparently shimmed properly.
This past weekend I went to replace my tie bars (they had a slight S kink to them), obviously being a mini one of the bolts was rusted on so I removed the lower suspension arm along with the tie bar and hammered it out. When I went to replace everything, needing to refit the lower ball joint I found that the threads were completely ruined. Bare in mind this is a new ball joint, installed once and removed once both times the fitting and removal went very smoothly without needing to overly hammer/bash the ball joint to get it out.
Simply put, the ball joint's tapered shank bolt is utter and complete garbage. It has less than 2000km on it and has been treat well when serviced. I just don't understand. The grade of material used seems also quite suspect. It does not seem to have been hardened and is easily scuffed, bent and marred.
I have several genuine ball joint kits that can use and replace that bolt with. The difference in quality is ridiculous. The bolt is hardened, for example.