Lionel PW 681 - reverse only

Switch the connections at the brushes to confirm whether it it a mechanical or electrical issue.  Then let us know.

As you are working on the e-unit, make sure that the plunger goes up and down, and that it catches on the plastic barrel and that the barrel rotates as the plunger goes up and down when power is applied and removed. Do not oil the plunger - it's just not a good idea for long-term reliability.  Make sure it works smoothly and does not bind.

The e-unit  barrel can be replaced pretty easily by spreading the e-unit carefully with a small screwdriver, and that should be your next step. Be mindful of the finger contacts near the barrel - they should not be touched if possible.  

If a new barrel doesn't help, you can next replace the set of finger contacts that ride on the barrel.  My 681 had a finger contact that was worn away exactly where it contacted the barrel , and eventually the engine direction became erratic.  A new set of fingers (there are different arrangements, so be careful) fixed the problem.

   Replacing the fingers took more patience than replacing the barrel, so I would do the fingers as a step2 replacement if the barrel replacement didn't work.

After that, between the plunger operation, barrel, and contact fingers, that's about it.  Good Luck.

As a general comment, I'm not a fan of spraying the e-unit with contact cleaner.  It may work in the short term, but it is moving the dirt around, not removing it permanently.   It would be much better to use a cotton swab with alcohol to carefully wipe down/polish the metal rings on the barrel.  A little bit of elbow grease, so to speak, will be more thorough than a spray. Don't use sandpaper or anything abrasive to clean the roller either. You want it to be as smooth as possible.

Everyone probably has their own methods to handle e-unit issues, but this is what I've done and it's been successful for me and my 681 that used to be my Dad's - it still runs great.

It does cycle into neutral but it only cycles back into reverse.

Rob - I will try reversing the wires and see if that helps. It looks to me like somebody tried to fool with it in the past so no telling if they got the wiring reversed.  All of the wiring needs to be replaced anyhow as it is frayed and falling apart.  But at least the motor has life enough to go at a good clip in reverse.  

Pennsylover - I took an E-unit apart 2 years ago and it took me about a year to stop cursing after  trying to get it back together.  I did it and that one worked fine afterwards.  I am really hoping to not have to do that to this one but I hear what your saying about moving the dirt around. I'll try the alcohol and qtip method.

Thanks for the tips on things to look for and try.

Ed

Larry,

I don't remember of if it cycles once pr twice before going into reverse.  I'll have to look at it this afternoon and see if that is the case.

Thanlks,

Ed

Well I worked up the courage to take the E-unit apart for a thorough cleaning as advised.   Amazingly, it went back together with little effort and even more amazing it works great now.  As they say, even a blind squirrel can find a nut once in awhile.

Thanks all for the help,

Ed

@Ed Walsh:

Glad to hear it--you may have inspired me to get to work on my PW 675.