au s1 v8 auto irs vibration in reverse, some vibration at idle.

[mif73]

Hi again.
I have a somewhat strange issue as i seem to have a small vibration at idle and a larger vibration in reverse under load with the brakes on or when accelerating under load in reverse only.
The car also feels like it has a looseness in the driveline when on and off power and a little wiggle when the converter locks and unlocks up at highway speed or when the cruise control engages and disengages.
The irs is in good condition with new bushes and joints and wheel bearings, the diff has a tiny bit of backlash.
The half shafts have almost nil backlash.

With the bonnet up in drive and loaded a bit with the brakes on, the passenger engine mount does not seem to lift much, but in reverse loaded up it seems to lift a little more on the drivers side.

I think the vibration in reverse and the engine lifting a bit in reverse on the drivers side and the loose driveline feeling are related.

I have never really come across a car with failed drivers side mounts but anything is possible i suppose.

Any ideas?