Gears locking up on a 628.

[mgbbob]

I purchased a 628 and it was not functioning.  I have taken the unit apart and done some looking.  I think I will eventually need to clean or replace the eunit but for now I just want to make sure I can get it running.  When I apply power it tries to run.  I have pulled/cleaned the armature and all seems to work when not fully assembled but once back together something is locking it up.  I suspect something is wrong in the gear set but with the trucks in place it is not easy to get into.  Any suggestions?

Also, what is the best method of removing the truck covers on the outside.  I don't think I have done one of these before.

[ADCX Rob]

Try running it upside down in a cradle, and squeeze the aluminum motor side frames together to see if this will get it going.  The motors loosen up and the armature gets out of alignment with the drive axle.

If you can confirm this, there are a few fixes.  Let us know.

[mgbbob]

I will give it a go in the morning

Thanks,

Bob

[mgbbob]

I haven't gotten the unit to run but I can confirm there is some movement in the aluminum frame and there are scuff marks on the field and armature.

[servoguy]

If the armature is touching the field, the motor will not run.  

The last time I had this problem was with a 44 ton loco.  This was more than 40 years ago.  What I did was simple.  I took a pair of needle nose pliers and twisted the aluminum side plates to tighten up the lower part of the motor.  This was quick and easy. 

[cwburfle]

Turn the engine upside down and try to run the motor. Push the plastic bottom plate from side to side. The motor will start running, or run better with that plate pushed to one side.

The Lionel factory service manual recommended using a center punch to dimple the side frames to tighten the plastic bottom plate.
I used to wedge paper matches (with the head cut off)  between the plastic plate and the metal side frames.

 

I expect Servoguy's technique would work, as would the factory recommendation. But if you get it wrong, the matchstick method can easily be undone

[servoguy]

I can't recommend hammering on the motor.  If something breaks, the motor is trash.  What I suggest is relatively gentle.  It only takes about 5 minutes.