Hornby R2782XS gears, what sort does it use

[ColinB]

I have got a Hornby R2782XS that I am trying to fix, that has got issues with the wheels not rotating freely. I have removed the motor and the wheels turns perfectly, so I suspect the gear train. Does anyone know what gears I need? I found the Service Sheet and it says I need a X8849, but when I look at Peters Spares there appears to be 4 types, locked/free moving, 13.8/11.3. Now as this loco has an issue with the gears and I don't know its history, what one should I use to replace it.