My Hornby James won't move because of disconnection with the gears.

[Nathan-1240996]

I got my James second-hand from eBay and when it came it would not run and just make a grinding noise, it would run but it was like a 50% chance. This was the norm but now it just makes grinding sounds.

I looked at the mechanism and noticed that the gears spin but the wheels at the back don't move. The front wheels are just fine and can't move left and right, but the back ones can and I believe the gears aren't connecting because the gears on the wheels move out of the way. It also can't be out of gauge because the wheel fits perfectly on the rails.

Is there anyone who knows how to basically prevent the wheels from shifting left and right so the gears can connect?

[Going Spare]

The grinding noise was created by the gearwheels not meshing properly and they may have been damaged by running the loco in that condition. Although the loco runs apparently perfectly on your layout, one of the rear tender wheels may have come loose on its axle and moved outwards. The spacing between the backs of the wheel rims (not the gears) should be no greater than 14.5mm. Checking and adjusting the spacing will probably be easier with the drive unit out of the chassis frame: to do that, insert a bladed screwdriver between the rear of the motor housing and the chassis frame and lever outwards to release the lug on the housing out of the cut-out in the chassis frame. Also check that there is no wear or damage to the gear wheels and particularly to their teeth.