Posted 19 July 2016 - 11:41 AM
It must not be tight. The Rover manual requires between "no nip" and 2 thou end float. If it is tight in a few spots only, lapping may improve it, but not always. What you must never do is adjust shimming to take up wear, because once it has gone oval, it will be tight at extreme angles, and will fatigue the pin, which will break.
That is generally true of all adjustable ball joints. They rely on the ball remaining spherical, albeit on the Mini it is two concentric half spheres. The reason for that, by the way, is that the vehicle weight is carried by the top joint on the smaller radius, about which the steering arm has more leverage, so less friction is imposed on the steering. Attempts to substitute more hard - wearing joints may fail due to increased friction.
I agree that quality is abysmal nowadays thanks to certain parts suppliers who are more than willing to take your money for third rate and possibly dangerous junk.
I see that Delphi, a very major supplier to the automotive industry worldwide, still do Mini ball joints. I currently work for an unrelated part of Delphi, so my opinion may be biased, but I suspect that their ball joints will be ok. They also do steering rack gaiters and CV joint boots, amongst other things, which I expect to be made of better rubber than those from an incompetent supplier who has been under criticism lately.
I don't get any commission, and am only a temporary contractor at Delphi, working on ECUS for large diesel engines, but I will be interested to see whether anyone tries Delphi parts and how good they are.