Large Scale Central

Bachman Large Scale 2-6-6-2T motor/truck problem(?)

Ran my BM Mallet few days ago, great fun, ran fine.

Tried again today, and the front truck was frozen and back truck made crunching noise!

So are there two problems suddenly? Or one related problem? Went on the BM site and got the exploded diagrams. Followed the directions to loosen the boiler.

I took off boiler and dropped both trucks (a LOT of stuff in there), the motor is vertical over each truck. Multiple plugs to pull, caution advised.

So I found that the rear truck motor was loose, which accounted for the grinding sound. Further investigation revealed that there are two screws holding the motor to a collar on the top of the truck. They are inserted through the collar and into the motor casing from below (the truck side) Both missing! That is clearly the problem, no sign of the screws in the truck, where they would have fallen, but the truck is open on one end, so they are gone, Somehow need to find them somewhere, starting with BM I suppose.

A poster on the Bachman forum had the same problem several years ago but apparently did not lose the screws- they may be #10613 but very hard to tell from the exploded diagram.,8533.msg70326.html#msg70326

The front truck motor is secured properly, not sure why it was not operating, That issue is yet to be dealt with.

This is a continuing saga, stay tuned.

I will post on the forums and see what I come up with, never bored with large scale trains as a hobby.


Check that one of the screws in the siderods didn’t back out and is jamming the works up. I had that happen on a HO loco once.

I sometimes find when doing maintaince on engines that I find something loose, or sometimes broken. I treat my equipment very gently, so I wonder why this happens, but it does from time to time. All my engines are LGB so I expect them to run like a Swiss watch, but we all know this will not happen and maintaince is always needed. I would say after your post that a good maintaince schedule is needed, I don’t think that all would go wrong over night.


Thanks guys

Now an update:

  • I thought the screws could be lost from an open truck assembly, but is seems that if they drop off they should be contained in a closed gear box, (part # 00502) which would also cause problems for sure. However I examined the gear box as best I can and cannot find the darn screws.

  • I called Bachman and a very nice lady is sending me two new screws #10613, which I appreciate.

The next thing will be to get the new screws, install them, verify the rear truck is working, then examine the front truck to see if maybe a screw dropped into that gear box Chris.

And John, I should mention that I found 3 other screws somewhat loose in the innards of the rear truck. This is not an easy or casual thing to check, so a word to the wise.


As that guy on the Bachmann forums found he had loose screws in 2009, I suspect it is a manufacturing issue. And bound to happen when you attach everything with screws. The diagram for that loco has dozens of them.

In my experience Bachmann gear boxes are full of white grease, so it seems more likely your screws are sitting in a corner and are unlikely to get in to the gears. The screws are almost certainly steel, so you could try your big strong magnet?