I have a wobbly cage which is affecting shifting performance and chainline alignment i have taken it apart and cant work out if its the bit on the inner cage or the cylindrical washer that slides over that inside the tension spring.

can I buy new parts to fix this wobble? if so any part numbers available?

I think this is what I need

http://www.sjscycles.co.uk/shimano-xtr-rd-m972-p-axle-assembly-5wj-9804-prod34426/

will have to call them tomorrow to ask if this will work? cheaper than a new mech as all other pivots are ok.