My Steering/Front Tyres Chattering While Braking At High Speed

OK, the symptom is simple and could mislead to other problem. The main symptom is when the car is moving at high speed, range from 70km/h and above, and sudden brake is needed, the steering wheel chatters. It was obviously felt that front tyres vibrate vigorously. Brought the car to a mechanic, he test drive the car and insist if nothing is wrong with the brake lines, or anything of the front tyres, then it may be the brake disc itself. However upon checking, he jacked up the car and we found out that the front tyre have some freeplay (when you try to push in and out at the same time, show loseness). Then he suspected it was the tie-rod assembly, both sides. The tie rod assembly is covered under the black protection boot. See figures below. Got them changed, and test drive, YAHOO!! Solved. The logic behind this troubleshooting is that, the other end of the rod is connected to the tyres while the other part (with bearings) connected to the main rod. When we brake, the other end will have to stop while the other end have numerous freeplay that enable it to move vigourously due to the braking force/shock. And remember that an alignment work is needed after tie rod works done.