About ten years ago I rebuilt my Land Rover on a new galvanised chassis, using many new parts. Sailed through the MOT no problem. Within a few weeks however I had a huge amount of play in the steering wheel.
The cause of the problems in no particular order.
1) Front axle U bolts had stretched over time and entire front axle moved as steering turned.
2) Some of the studs securing the ackerman arm to the swivel housing had worked losse, despite look tabs and swivel housing became loose. I sssume these studs had stretched too and had no end of problem obtaining ones that could be torqued to the figure in the book before shearing.
3) The steering box support bracket had become loose on the chassis. I could see the whole bulkhead moving as the steering was moved. This I put down to the new smooth galvanised chassis and coat of paint on the bracket not offering the same friction as the old rust bond between the chassis and bracket. Swinging on the nuts with a bigger spanner cured that problem.