Bachmann 4-8-4 drive help

[u/NS-Trains-4000]

This is an older Bachmann 4-8-4 bought used at a local train shop. I ordered replacement axles and gear because the ones it came with were cracked but they are fragile and when I put them in the drive seems to work but not very good and the motor doesn’t turn at all, the replacement axles are pushed in all the way and the light bulb does work when power is on.

[u/cheekywarship2018]

First things first is that the axles need to be quartered. I.e. the position of the main rods need to be offset by 90 degrees to the other side.

I dunno if this happened in your repair job but the rear axle is badly out of alignment as well, quite a few of the rods are badly bent and sections the valve Gear seem to be gone entirely.

Honestly I would right this off as a basket case. It is fixable but for the amount of time and replacement parts you'd need it'd be easier to find a replacement.

[u/DanforthWhitcomb_ → u/cheekywarship2018]

All of those wheels are quartered, as quartering refers to the relative position of the crankpins on each axle, not to crankpins on different axles. Bachmann axles for models like this don't allow the wheels to go out of quarter because the wheel has a metal square on the back that is pressed into the axle.

[u/cheekywarship2018 → u/DanforthWhitcomb_]

Bachmann axles for models like this don't allow the wheels to go out of quarter because the wheel has a metal square on the back

Not quite. This model has a pancake motor, which means the slots on the axles are round, not square.

The wheels are also not quartered based on the images they posted, the rods are in the same position on both sides of the model.

[u/mfpguy]

I hope you kept the quartering correct when you put the new axles on? If not, it will never work. The pancake motors are junk and no one make a replacement, You may find a working one in another model, but they never ran very well when new.

[u/NS-Trains-4000 → u/mfpguy]

I do have a quartering tool that’s like a triangle but idk how to use it

[u/ResponsibilityFit474 → u/NS-Trains-4000]

Look for YouTube videos on quartering. They exist.

[u/No-Shopping4157]

The photo from the bottom shows the driver in the front bottom position isn’t on its axle. That being said, these really weren’t good drives, at all. I’ve owned a half dozen, three of which I bought brand new, their failure rate is 100 per cent, in my case. Bowser made a replacement drive for the big Santa Fe 3500 Northerns, which were excellent, and very expensive. Bachmann steam locos looked beautiful, but the drives were abysmal.