I have a Husqvarna 10-30e that wont move forward or backward in any gear. The odd thing is while in gear I can freely push it forward or backwards with no resistance. It almost feels like it's in neutral. I checked the belts and friction plate and everything seems ok. I took the skid plate off and noticed when I move the wheels, I can hold the hex drive shaft while in gear, and it doesn't move but seems to slip. Do you think something in the gearbox is broken?