Mark and all,
The fit of the motor bracket is tricky. I loaned my All Nation steam loco instruction sheets a few moths ago to someone who wanted to make a copy of them. But they've not come back. I will try to recall. I sold my 4-4-2 two years ago, so I no longer have a ready reference.
The bracket has a horseshoe-like end which attaches to the motor with a pair of 4-40 round head machine screws. The holes in the bracket I had were a little oversized, which allowed for some wiggle room in adjusting the fit of the motor. I think there were motor bracket tail end mounting screws too.
The other end of the bracket has a toe-like extension with one (?) hole in it for another 4-40 (or 6-32) machine screw to hold it to the fame. That end is where you adjust the mesh of the worm and drive gear on the axle, with a thin washer or two under the toe. The drive gear mesh needs to be about 50% into the worm so that its a good fit, but not loose enough to have any gear tooth backlash. Nor so tight that it binds at any point when the worm shaft is turned by hand. Once that is set the other screws holding the motor bracket to the fame can be tightened, then check the gear mesh again.
It's a fussy job to get it right, but once set correctly. that drive can outlast us all. It reminded me in part on how a mechanic sets the mesh of a pinion and ring gear in repairing an automobile's rear axle, but those days are gone now.
Now here is where I need to see an instruction sheet, because I'm fuzzy on just where the motor bracket toe meets the fame. Is it on one of the round spacers holding the fame sides together, or does it reach down to the bottom plate that holds the driver bearings in place?
Either way, the fit of that motor bracket toe screw also determines how far back or forward the motor and bracket will be on the frame. On the 4-6-0, the bracket toe screw hole should be in front of the middle, main driver axle, to center the worm over the main driver's gear. Be sure to check the worm to drive gear mesh.
Onward!
S. Islander
