Now then Ken, all I can think of at this distance is to give you a list of things which I would check out if it were my car.
I don't think the problem will lie outside of the clutch / intermediate shaft assembly so check first of all on the condition of the intermediate shaft bearings just behind the clutch - they should show no signs of movement whatsoever. If there is movement here remove the bearings and check if the play is in the bearing itself or in the housing where the bearing sits or on the shaft inside the bearing. both of these areas should be shiny clean like new, If there is any black powdery deposit in the aluminium casing it should be replaced or repaired with a "top hat" insert. if the shaft shows brown rust like deposits then this is bearing creep and means a new shaft is in order. Check these areas dimensionally, to be certain, before replacing either. If all is good with the bearings and their fits then do a check for true running and straightness of the shaft. Clamp the aluminium plate securely on the bench and use a dial test indicator to check for true running of the part of the shaft where the inner centa rotor fits and then check the flange where the clutch is mounted - both on the outside diameter and also on the face. if the shaft runs out by more than 0.05 mm total indicator reading then take it out and check it all over between centres on the lathe to try and identify where the run out is. Check also for any damage to the shaft and its faces and shoulders ( I have seen some butchered items in this area!) you may be able to re-machine the face where the clutch bolts on to get this true and it might be possible to straighten the shaft under a hydraulic press if it is slightly bent. If all is good here then mount the clutch flywheel / ring gear on the shaft and make sure this all runs true with the DTI - check for damage to the face of the flywheel where it mates with the flange on the shaft. A check of the true running of the gearbox input shaft might also be good but I doubt if this is where your problem lies
My support bearing is designed to prevent the shaft bearings from being forced out of line by the somewhat unpredictable forces exerted by the rubbers in the Centa coupling, especially as they start to fail, but will not fix something which is running out of true to start with. My kit will give you a more rigid set up, much smoother running, reduced vibration, high temperature resistance and the ability to change the rubbers in 30 mins. Sadly, it will not fix something which is already broken - sorry.
The price of the Centa upgrade kit is £356:00 plus a bit of extra postage to Aus. You can get the mods for the quick change done by any competent machine shop and the drawings are here.
http://www.bleazey.co.uk/M3Wstage3text.html Do let us all know how you get on.
Good luck and don't hesitate to ask if I can be of further assistance.
Phil
