[AndyVR]

Had a brand new aftermarket rear subframe fitted which came with all new bushes.

It took the garage a long time to do, they also replaced a rear wheel bearing at the same time. They did basic wheel alignment camber and toe with gauges, but needs a full 4 wheel alignment doing which I booked in advance for next week.

When I drove it away from the garage I started to notice that when slowing to a stop, a low pitched noise appears that like a low whine and scraping noise.
If I pull away again at lowish speed then brake, it doesnt reoccur.
Seems like you have to be driving at 30 mph or so, then come to a stop, it's always there when slowing between say 10mph and zero, engine hot or cold.
Driving at motorway speed seems ok, at least I can't hear anything, and it feels smooth.

It's a manual gearbox.

The garage are closed now for a few days, so thought I could do with some thoughts on this in advance.
I read on another forum a theory that the subframe being misaligned could cause diff noise like this, but in that case it turned out to be something else.

Is there anything that could have been done wrong, like the position of the diff relative to the propshaft coupling? I don't know what those couplings are like or how much misalignment they can compensate for.

If it could be subframe misalignment by not being free to move when tightened up to the chassis, I could do with getting this adjusted before it goes in for wheel alignment next week.

Any thoughts appreciated.