These joints cause a lot of problems because it is hard to detect wear even when they have completely failed. The effect can be serious weaving from the back of the car.The only sure way of measuring failure is to to check the cars's front track, move the car forward a few centimetres and check the track again. If the measurement is different then the bottom ball joint has failed.They sometimes need to be heated up to be removed. There was a Talbot tool for carrying out this job but they broke quite easily so not many left.