These sort of threads give me the feeling that there is intent to bodge a job, in order to make a quick profit, selling on something to an unsuspecting buyer.
My Kango jack hammer was a typical example – it worked for about ten minutes before failing. Inspection of the failure showed a right bodge by a cowboy had been made to get rid of the item.
My proper repair has lasted since – I made parts (and actually found parts left in the hammer from the original failure) as well as a few needle bearings. Still finished with a good jack hammer for about £40, but annoyed with the cowboy’s bodge.