The brief
The Golf was vibrating hard enough at idle to feel through the steering wheel, there was a clunk on every gear shift, and the engine knocked against the bay over speed humps. Three signs that the drivetrain wasn't being held the way it should be.
The engine and gearbox don't bolt straight to the body, they sit on rubber mounts that take their weight and soak up the shake. As the rubber ages it sags and cracks, and once it does the engine can move around more than it's meant to. That extra movement is the vibration coming through at idle, the clunk as the drivetrain rocks on a gear change, and the knock when it shifts on its mounts over a bump. Mounts that have all sunk together produce exactly that.
The diagnosis
On the lift, each mount got a pry-test. The main engine mount and the gearbox mount had both sunk visibly with the rubber cracked, and the lower torque link, the long arm that stops the engine rocking forward and back, had play in its bushes. All of the drivetrain mounts were tired at the same time.
When they go together like that, you do them as a set. Replacing one fresh mount next to two sagging ones just loads the new one harder and you're back in soon, so the call was all three.
The work
The engine and gearbox were taken onto transmission jacks to take their weight, and each tired mount came off in turn, the engine mount, the gearbox mount and the lower torque link. New VAG-spec parts went in across the set, every fastener torqued to the manual figures.
With everything bolted up, the drivetrain was checked to be sitting square in the bay before the engine was let down to load onto the fresh mounts.
A road test confirmed the shake, the clunk and the knock were all gone.
The outcome
Smooth at idle, no clunk on shifts, no knock over humps, and no vibration through the wheel.
The Golf went home with the drivetrain held properly again. Engine mounts wear as a set and they take the rest of the drivetrain's comfort down with them, so doing all three together resets the whole thing rather than chasing the next sagging one a few months later.
