Maybe not relevant Joe and both of these are a long time ago now (one 30 years ago) but on an old 740GLE manual i bought as a spares car, that would do the wobbly stick trick when it fluffed a bit, that was down as Bob suggested to worn mounts on the gearbox and engine but also wear in the gear linkage from lever to box (M46 box on that one) and as the car hadn't been used for a while, ran a bit lumpy anyway.
The second was a fairly young (3-4 years old) low mileage 240 estate with the M47 box, that had slightly worn layshaft bearings in the gearbox so with the clutch out at idle, it quite often "zizzed" a fair bit on the gear lever.
In 4th (direct drive) it went totally quiet but in 5th, could occasionally "zizz" a bit at certain revs, the first 3 ratios it also did the same but not often in the lower gears thankfully.
Maybe useful, maybe not, but food for thought either way!
