Pretty sure I have. I’ve touched just about every part visible in the loco with that wire
The brush springs on these motors are very light and easily knocked out of place. In your photo you can see the tail end of the torsion spring sticking out to the right of the loco. It needs to be snapped back under the metal tab on the opposite side. As it is, there's no spring tension on the top brush.
These early 70's Bachmanns were better than the later pancake versions, but once Tyco opened that Pandora's box many manufacturers ditched more expensive designs like this. These motors were designed a lot like the large scale slot car motors from the 60's. and ran well enough even if they were noisy. I've replaced the motor in one of mine with a good can, replaced the shaft couplings with slicone fuel line tubing, added a ton of weight, and it runs better and quieter than a super weighted Athearn blue box.
The wheel rims coming loose is a common problem, and the can be glued back to the hub with a little CA, as someone already noted. If you don't know much about the internals of model locomotives, old units like these make for a great test bed and learning experience.