Not sure what this problem is!

[27litres]

A little late to this conversation Jim, but i had an issue a few years back now with my A4.
Had a difficult time diagnosing it.
The car would suddenly start feeling like someone had nailed a lump of wood to one of the rear tyres. Just as it get to the point of pulling over it would go away.
Finally associated it with road bumps and the suspension getting close to bottoming. That lead my mechanic mate to say "It'll be dry grease in your rear CVs".
The grease near the edges of the CV outside of normal movement will dry out over time, and that because the rear CVs never articulate a huge amount, the dry grease is near the edges. Get a decent movement of the suspension over a bump or rut and a bit of dry grease can get pulled into the CV and be a solid lump that the CV must pulverise into submission!
He was right! Cleaned and regreased all 4 rear CVs and the problem never returned.

May not be your problem, but food for thought...

[The_Laird]

The issue seemed to ga away for a while (but maybe it was that I hardly drove it in lockdown), but it’s back again! Nowhere near as violent as some of the descriptions here or in MJ’s TC thread. But it does happen at around 1800 rpm and, because it’s not too bad and only lasts a couple of seconds, no-one else seems to notice it.

But, at over 190K miles, I know that the gearbox is on borrowed time, even though it’s been to Mackies at least a half a dozen times.