The Loco derailed on a corner. When I put it back on the track I found that the driving axle wheels weren't gripping the track (they spun rapidly but the train moved slowly). I could partially correct this by pushing on the side of the body. Anyone got any idea what the problem is and how to fix it?
If this is actually what has happened, your best bet is to get in touch with Bachmann and tell them what has happened and ask for a couple of replacements. They took a week to send me the replacement driveshafts, but that was because they hadn't yet arrived in the UK (I needed both, as one had broken and the other had fallen out and got lost, how I do not know). Yours should arrive much quicker than mine did. They didn't charge me anything for them.
To repair the loco, you first of all remove the body by undoing numerous screws (4 by the buffers, and 4 in the middle by the fuel tank). Be careful how you remove the body because of the wires leading to the lights. You can undo the bogies by means of a screw in the top of the chassis weight. It is then easy to insert one end of the drive shaft into the flywheel, and the other fits into the bogie as you replace it. Look at the exploded diagram for help. Reassembly is the reverse of disassembly.
In that case you should return it to the shop you bought it from. I would expect a reasonable response from them; ie repair, replace, or refund. You are amply covered by standard consumer law in the unlikely situation of their being awkward. However, I would be really surprised if there was any quibble over a recent purchase. There is also the printed guarantee that you will find somewhere in the box.
If you didn't buy it from a shop (eg you got it on ebay) then you're probably on your own, but you only gets what you pay for .
Goods still have to be of saleable quality even if the warranty is only six months. It would be interesting to argue in the small claims court that a loco costing around GBP100.00 should be expected to last more than six months. I can't believe such a case would fail.