[morris]

I'm still looking into it. So far I've tested the following:
- rear wheels off
- spacers off
- discs off

The problem persists. When I had my first IVA test and the examiner ran the car up to 70 there did not appear to be any vibration visible, audible and he didn't mention feeling it (I would have as it's not bearable). That got me thinking about what had changed and I realised I had swapped the rear brakes over from my E46 since that point but at the second IVA, we only hit 25-30 round the yard. I was hoping that it was something to do with the brake swap. Unfortunately this turn out not to be the cause as even with the discs off, it still shakes.

Unbolting the drive shafts from the diff and then unbolting the prop from the gearbox output are next. The bolts are all tight and the same length. I did have to modify the heads on some but tested they were all within a gram before installing. The flanges do appear to be mated properly both ends and the UJs are aligned. The welded on weights on the prop are still intact and there's no evidence of physical contact with anything. I'm also suspicious of my gearbox mount but would think that would cause a clonk on acceleration or coming of the throttle quickly rather than a shaking.

I've found a test to rule out the flywheel or clutch so will try that too.

I'm a little worried that I've ruled out the engine too soon because it doesn't vibrate when just rev-ing freely. Could worn crank thrust bearings be a factor? Would rev-ing in neutral but with the clutch engaged rule that out? I'm thinking of the force down the crank when under load.