The LTH has a hydrostatic box, make sure the by pass lever is not pulled out, make sure the brakes are not binding ( disc brake on the side of the gearbox ) make sure the belt from the engine too the gearbox pulley is tight and in good condition, failing the above change the oil in the box sae20- 50 if this does not cure it, it will need a rebuild/ new gearbox, there are parts available for the hydro-gear box, but this is a specialist job.
Husqvarna man, March 2010
