Lionel 627 LV Postwar 44 tonner

The problem is almost certainly play in the black plastic plate at the bottom of the motor truck. It acts as the lower armature bearing. This is a well known problem with those motors.
To figure out which way the plate has to go, try to run the motor in the "bad" direction. With power still applied, turn the engine over and push the plate to one side, and then the other. It may only move a tiny bit, but in one direction the motor will take off.

There are various ways to make things tighter so the plate stays in place. The Lionel service manual suggested using a center punch to dimple the metal side frame. I have wedged a paper matchstick between the metal side frame and the plastic plate. A drop of CA, and the matchstick isn't going anywhere.
I am certain other people will add their solutions.

Not sure I follow the advice "with the power still applied turn the loco over".  Since I have a few locos with similar motors that exhibit this problem to some degree I am very interested in a simple solution.

I use the same method CW uses to fix all of those motor types. There is supposed to be a ball bearing in the bottom of the plastic plate that holds the armature shaft. The problem is often the plastic bearing plate is too far to one side. If you look inside the C shaped opening where the armature spins you can usually see which side the armature has been rubbing causing it to climb upward. You then move the bottom plastic plate to the opposite side and hold it in place with a wedge of plastic or card stock. I usually put a dab of CA glue there once I have it correct.

Rob

quote:

Not sure I follow the advice "with the power still applied turn the loco over".  Since I have a few locos with similar motors that exhibit this problem to some degree I am very interested in a simple solution.

You have to be applying power to the locomotive with test leads / alligator clips.
Start out with the locomotive upright so the e-unit can cycle.

quote:

 If you look inside the C shaped opening where the armature spins you can usually see which side the armature has been rubbing causing it to climb upward.

In my experience, the armature doesn't always rub. Often it's just a matter of misalignment between the worm and it's gear.

OK, so there is supposed to be a ball bearing in the bottom plate? What is the part number for the bearing?  I have some but they are too large for the hole. 

The bottom plastic plate is tight, no movement, but the top metal plate is loose on the armature end. How do these get 'restaked'? I think the looseness of the top plate is also causing an issue with the motor.  

Also where does the bare wire coming off the windings get soldered?  One end goes under the one brush cap screw(solder lug), where does the other go?   

The other copper wire probably goes onto the center tab on the brush cap. 

Rob

Thanks Rob, that's where I soldered it. 

I finally fixed it!! The Eunit needed a new drum, had to resolder the wires for the E unit, 'stake' the top plate on the motor truck to keep the armature from moving too much and of course a good cleaning.  I probably took the E unit apart at least 5 times before I got all the gremlins.  

Did you get the engine with the repainted frame? The 627 should have a black frame, not red. The 629 Burlington was the only 44 ton with a red frame. The 627 was the only engine in the series without a operating headlight, which I see the headlight bulb socket is not present.

It looks to me like there are marks from a lamp socket. Perhaps someone put a 627 shell on a 629 frame, and removed the socket.

I tried illuminating a 627 loco once. The light glowed brightly right through the red shell. I wonder whether that is the primary reason the loco was sold without a working headligiht.

The part number for the ball bearing is 600-110.
I can post the size when I have access to my notes. I am on the road right now.

I looked up the number in Olsen's free library.

Chuck,  I got it with the red frame but I know someone somewhere had done some work on it.  Good to know it's supposed to have a black frame.  I was thinking of putting a light in it but decided it just isn't worth the time or the money for this engine.  

The engine was given to me by someone who could not make it work, they had given up on it and did not 'do' E units.  

C.W.  Thanks for that part number.