Knocking wheels and wobbly steering wheel - 'driveshaft mate' or something else?

[cwathen]

Sax failed the MOT in October on steering rack gaiter, outer CV boot, and suspension arm ball joint (all offside). Also the anti rollbar bracket broke when dismantled and had to be welded back together. Prior to the MOT it never demonstrated any hint of steering/handling/suspension problems at all, and I was daily driving it 200/300 miles a week, mainly motorway.

Almost as soon as the MOT work was done, I started getting knocking on hard right lock, and a feeling hard left lock was 'soft' as if the rack hadn't quite gone all the way over. Should have taken it back to the garage but didn't as apart form hard locks it was fine and wasn't planning on keeping the car that much longer anyway.

Did about 3000 more miles in it but then one day starting getting both a constant knock from the nearside whilst driving home one evening. It was enough to make me come off the motorway and continue on local roads. Now when turning at slow speeds the steering felt uncertain with sort of 'lurches' through the steering wheel, but not at any constant replicable point.

The next morning I jacked it up and took the front wheels off. Thought I'd found it - the offside wheel arch liner wasn't refitted properly and the bottom of it was fouling the CV joint on full right lock, and the 'soft' full left was literally the tyre pressing the liner back. It had now buckled into that position so I cut a section away and thought I'd solved it as the car now seemed fine.

This was a red herring - the nearside issues came back again.

Seems that the car will drive sweet as a nut from cold until it's been going for about 15 miles or so, then the problems (may) start. But they're not replicable, sometimes nothing happens, sometimes it feels like it's about to fall apart. I've had no choice but to carry on using it for my work commute (although now all on local roads in case it breaks) and it's not even the same across the same stretch of roads on different days.

So is this just another knackered Sax driveshaft, something else gone, or it wasn't put back together properly after the MOT work?