65 year old Santa Fe 2343 rear motor dragging

Check that the new brushes are not too long or that the length has caused increased brush spring pressure. May or may not be the cause.

The wheels are rubbing on the truck casting. Look at the back of the wheels.

If you removed the worm shaft and bearings in the trucks during your cleaning/re-oiling operation, did you put the bearings back in correctly?  The holes are NOT in the center of the bearings, and both bearings must be with the shaft hole in the lowest position....i.e., closest to the wheel axle gears.

This same phenomenon happened to me about 60 years ago!  As an 'I-know-everything-and-can-do-anything' kid I saw teardown, cleaning/lubing, re-assembly of the guts of my treasured 2343....all without the permission and guidance of Dad...as noooooo problem.

So when the trucks were exhibiting weird go, no-go motion, I flushed with panic and began to re-examine what I'd done....before Dad got home from work.

And I was soooooo proud of myself to find out that those little worm shaft rectangular bearings were the culprits!  I deduced that the holes should be in the lower position.  It then ran like its old self!

It was, indeed, a childhood experience never to be forgotten!

FWIW, of course...

KD

Lionel Parts posted:

The wheels are rubbing on the truck casting. Look at the back of the wheels.

I had one that behaved like yours. I finally gave up and took it someplace to be serviced, and this it what they found on mine, too.