Check the gearbox brake is not binding ( in bypass can you push it back and forth) if ok check the drive belt to the unit is not slipping, if ok, you can try an oil change, however the damage in the unit may already be done. It may well need a gearbox rebuild, the UK spec machine had a Hydro Gear transmission, the US spec machine had a Tuff Torque transmission, the type and model no will be on a sticker under the seat pan, both units are repairable, however it is a specialist job, new units will be very expensive, parts are available from Husqvarna dealers if you fancy a go at rebuilding it yourself, it will very likely need a new centre section, and possible cylinder block and seal set. Check for scaring on the alloy centre section, and or broken springs in the cylinder block
Husqvarna man
August 2010
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix lawn mowers.