I to have a KH 4402 and have had it for just over Three years and don't do a lot of shredding with it and mine has exactly the same problem. I found this out after a good strip down because i thought it was only jammed (it may still be) but when i took the gear housing cover off i couldn't believe my eyes, gear totally stripped of half its teeth!! And, i have to agree with Brian 2010, it does seem to me to be a deliberate manufacturing design 'imperfection', plastic/nylon to metal is a massive error in engineering, its a school boy error ... or is it?
We're talking about our shredders, they're thinking about business which is a shame because if Lervia stuck metal gears in these machines and charged us that bit extra we could have a dam good machine and they will have a good reputation
Mark, October 2011