I have a 4 in one garden strimmer/pole saw/pole hedge cutter/brush cutter
that I bough on eBay some 7 years ago. It of unknown Chinese manufacture and
apart from having a new carb diagram a couple of years ago has performed
perfectly. Sadly this weekend the motor ran but the tool did not rotate! The
cause was a worn spline where the first shaft enters the clutch. At first
inspection it seemed to be the end of the machine's life but on looking
closer I managed a fix.
By sawing about 10 mm off the outer tube of the first section and re
drilling the locating hole in the side of said tube I was able to slide the
spline in by at least 15 mm more than it had been engaging from new. It
would seem that the locating hole had originally been drilled in the wrong
place only allowing the first 5 mm of the spline to engage, hence the wear.