Hi all,
I just acquired a Lionel PW 628 44 tonner. I tore the whole thing down, degreased, cleaned, etc.
Having a weird problem and I would like to see a motor parts diagram for that series of engines if anyone has one. My repair manual does not have a breakdown listed.
When moving the wheels forward (engine moving in reverse) manually they spin smoothly with slight force as you would expect. When moving the wheels in reverse (engine moving forward) it seems to sort of bind, but more of a subtle drag.
It runs fine in reverse. It will also sometimes run fine forward. When it doesn't it runs slower. Give it more power and it runs fine. It is like you need to give it enough power to overcome the drag, but not always. Sometimes it runs fine forward and slow.
With the armature out the gears spin freely in either direction. Gears look fine as well as the armature and it's worm gear.
The only thing I seem to notice is that the armature rises and lowers more than seems normal to me. I would say 2-3mm. When in reverse it is being pulled down towards the ball bearing and runs fine. When running forward it seems to lift excessively; at least to me. I wonder if that is causing a drag between the armature worm gear and the "main gear" it is engaging.
There is a plastic thrust washer on the top spindle of the armature and the ball bearing on the bottom in the plastic piece.
I have torn down and rebuilt every engine I own and I have never run into this before. In my opinion it is definitely a mechanical issue.
If anyone has the motor diagram or any ideas I would really appreciate it! I will be playing with/working on my trains a lot tomorrow and hope to be able to figure this out. It seems like it must be something very simple.
