The brief
The owner had been chasing a clunk from the front of the Touran for weeks. It knocked over bumps, sent a vibration through the steering, and the handling went unstable on rough roads. Other workshops had pointed at the lower arms or the links, but he wanted a proper diagnosis before throwing any more parts at it.
A clunk over bumps with vibration through the wheel can come from a few places, and the trick is finding which one rather than guessing. The front subframe is the cradle that carries the engine and the front suspension, and it bolts to the body through rubber bushings that locate it precisely. When those bushings collapse, the whole subframe can shift under load, and that movement is the knock, the vibration and the wandering feel, even though the parts hanging off the subframe are fine.
The diagnosis
A pry-test on the front showed the lower arms and the links were within tolerance, exactly as the owner had been told. But the clunk was coming from somewhere else: the front-axle subframe bushings had taken on visible deflection, with the rubber separating from the inner sleeve on one side.
So the right call was the bushings, not the components that other workshops had been eyeing. Replace those and the whole front end is located properly again. A four-wheel alignment afterwards to reset the geometry, since dropping the subframe moves everything.
The work
The engine was supported, the front subframe dropped enough to reach the bush seats, and the failed bushings pressed out. Fresh VAG-spec bushings were pressed in to the correct depth, the subframe bolted back up with new bolts torqued to spec, and the car rolled onto the alignment rig for a four-wheel set-up.
A road test confirmed the knock was gone and the front felt solid again.
The outcome
Knock gone, vibrations gone, handling back, and the alignment in spec, so the front tyres will wear evenly again.
The Touran went home tracking properly after weeks of the wrong parts being suggested. The lesson is a familiar one: a clunk needs a proper diagnosis, not a parts swap, because chasing the symptom around the suspension costs money and never fixes it. The bushings were the cause, and once they were done it was solved.