Swingarm bushes eh? Hmm.. don`t get me started... well there you`ve gone and done it now... so here goes:
I am also "preparing" to refit bushes to my late a10 hollow spindle job.There are all sorts of pitfalls with this job, not least the fit and quality of the bushes available. For starters, as regards the problem of misalignment of the centre tube when pressed in, the bushes themselves are rarely (ever?) moulded together accurately and the inner/outer tubes not parallel to each other, hence the misalignment when fitted mentioned above... Bushes often come with the inner bore too small to fit over the swingarm spindle,(again i speak re the hollow spindle version) so my second set
came from Kidderminster who had them ready reamed out slightly to fit the spindle, (a nice stiff fit by hand). This I regard as only the start!
I had looked at my swingarm (after a Titanic struggle to get the old bushes out) and saw that the bores were quite good and parallel.The O/D of the new bushes was far too big for the swingarm, with an interference of 15 thou. in places!. I decided remedial work was necessary if there was any chance of success, so i bought a piece of 13/16 silver steel bar from the local engineering supplier,(same dia.as the spindle) & set it up in my lathe to run dead true, pushed each new bush over it and spun up the lathe- it was like watching a camshaft!!! I skimmed the ends of the inner tubes true and square- and FLAT-where they butt up together -the makers insist on ruining the inner tubes here by chamfering/de-burring the ends of the tube at this most critical point- On the hol. spindle version there is precious little metal to butt up and take the clamping load when the spindle is tightened up-they soon come loose and dig into the frame, start to turn on the spindle instead of flexing the rubber, and burrow a great oval hole in the frame- believe me I know! I have also made up two small stepped stainless thrust collars to go between the tube ends and the frame to spread the load and protect the (repaired) frame plates.This means shortening the inner tubes by the same amount at their inner end (2mm) and pressing the bushes 2mm further in to accomodate, theres plenty of room to do it.To head off any centre tube misalignment, I have made a small collar to fit (tackweld)over the innermost end of one inner tube with a "catch" taper to recieve the other inner tube as they come together inside the swingarm to automatically correct any misalignment on assembly.I have also trued up the O/D of the outer bushes by skimming a few thou off so ALL is now true to the spindle bore(as they should have been in the first place!!)This has lost some of the O/D inteference fit, but I think it was excessive anyway.I will lubricate with Loctite on assembly for a "belt and braces" job I will let you know if all is a success
Bob.