784 Hudson, magnet rubbing on driving wheel

After the engine was in the box for 20 years, a forum member fixed the

problem so I tried to fix mine.

Just grab the magnet with pliers and twist. The magnet will come loose

but you may break the pins that were staked to hold the magnet in place. Move the

magnet over 1/16 inch and use a glue like Super Glue gel to hold the magnet in place.

Even with the pins broken, the glue will hold. The engine runs much better and will run better without the magnet than with the magnet rubbing on the back driver. The glue

is still holding in my engine.

The chug sound is much better if the 330pf cap on the end of the sound of steam board

the connects to the motor brush and carries pulses from the motor to the board is replaced with a .1mf cap.

Personally, I would trust JB weld more than CA glue for the magnet. 

I have had this problem with a couple of Lionel postwar steamers.  In one case, the magnet was loose and sliding back and forth.  I put a setscrew in one of the standoffs between the two motor side plates.  The next problem was the wheels had too much side play and would rub either end of the magnet.  I got some E clips that were the size for the axle and installed one or two of them to limit the side play of the wheels.  You can get E clips at Ace Hardware or Home Depot or???

The oil I used for the axles got on the back of the driver and on the magnet, and after is fixed the loco, I didn't notice much difference in the performance.  

Forgive me but I want to give this a bump for the weekend crowd.  I would like more input because I'm trying to decide if I want to return the frame I purchased.  Thanks.

I have a 783 that had the problem you describe.  I moved the magnet several times, to keep it from contacting the inside of the drivers, but it would eventually slide back again.  So I tried using cyanoacrylate super glue to stabilize it.  That held for a couple of months, but eventually it came unstuck again. Finally I tried superglue plus epoxy.  Once more, it was only a temporary fix. 

So I removed the magnet altogether.  No more problems, and the remaining magnets take up the slack just fine, with no noticeable lack of traction.

It wasn't on the bottom of the frame, as you describe -- I had to remove the shell to get at it, so evidently the 785 has a slightly different magnet arrangement.  But in my case at least, my 783 now runs 100% better.

My initial thought is remove the wheels and grind it some, slowly as heat will kill magnetism. 

I would use JB weld if I removed it too.

On plastic, tiny dove tail grooves, or toe nailed pockets, and a coarse sanding are suggested and sometimes needed, as really smooth surfaces, especially plastic are one of the few things it does break grip on.

I just finished working on a medium quality Modern era Lionel locomotive with a similar problem. The rear drive wheel without the gear was binding. At first I thought the wheels were pressed too far onto the axle, so I used a wheel puller to spread them a bit. The bind was still there so I looked closer. Even with a bit of play, the magnet was strong enough to pull the wheel over anyway, so it continued to rub. I pulled the wheel, and added a 671M-23 thrust washer between the wheel and it's bearing. Problem solved.