If the plunger is removed, polish the housing and the plunger with a very fine polishing compound with a Dremel polishing bit. Then clean both with denatured alcohol.
Also, in lieu of polishing, try applying a small amount of graphite lubricant to the plunger. There are arguments fore and against doing this, so you may want to wait until a few more offer their opinion.
I have 2025 e-units both ways, and they both operate equally well.
this sure sounds like a magnetized plunger which can happen after a lot of years of use. I would clean it like mentioned above but in addition you should make an attempt to demagnetize it. From what you’ve said I would bet that’s the problem.
With the plunger removed, gently rap the plunger shaft a couple of times with a hammer on a work bench. This removes the magnetism and the unit shouldn’t stick.
The usual way to demagnetize something is to put it into a coil which creates a strong alternating magnetic field, then gradually reduce the field to zero. A handy coil is the one in a Lionel e-unit. Put the armature into the coil, turn the coil voltage up to its maximum, then reduce the voltage slowly to zero. If your armature was magnetized, this should fix it. Wait–that’s the way it normally operates! I doubt that magnetization is the problem.
From the Wikipedia article “Magnet”:
A magnet being placed in a solenoid which has an alternating current being passed through it will have its long range ordering disrupted, in much the same way that direct current can cause ordering.
I have a demagnetizer in my tool repertoire that looks like a fat screwdriver with a cord to plug it into 110. The older audiophile guys will remember these. They were used to demagnetize the record and playback heads on cassette and reel-to-reel tape decks, necessary routine maintenance to reduce hiss and distortion. Then we got CDs about 23 years ago, not long after the invention of the automobile.
If this is for an American Flyer unit, since the pawl hangs up in the up position something I’ve done that works after the regular cleaning deburring you’ve already done is to SLIGHTLY bend the end that sticks out the side down and back. Not sure why it works but it has for me. Go slow and little at a time as it usually does not take much.
With all due respect Bob, I’ve done the rapping of the plunger a couple of times and it has worked every time. Now I always clean it at the same time so maybe it’s a coincidence, but this repair trick is not something I made up. Been around a long time.
May be, Mike. I just can’t see how it could stay magnetized in that environment. My e-units never see anything but DC; and they don’t get magnetized. They do hang up sometimes; but I’ve always been able to fix them mechanically, usually by restoring the original shape of the drum teeth. (I realize that that can’t be the cause in Ben’s case.)
Here is another solution for your problem. Lionel made a Plunger & Pawl assembly that uses a spring(part# 671-140. The Pawl is # 671-141) Anyway, I used these parts on a E-UNIT for a friends engine that was sticking. Problem solved! The above parts were used on the early versions of the 726 Berk & 671 Turbine as they had horizontal e-units & the spring pushed the plunger assembly down instead of Gravity. Try Jeff Kane at the Train Tender or Dr.Tinker’s Toy Train parts for the above. Hope this helps. Take Care.
I wasn’t able to locate any of the three or four tubs of Dremel polishing compound I had lying around. I did, however, on the suggestions presented here, hand polish it using Brasso, which failed to correct the problem.
I did also try hitting it several times with a hammer, thinking that I had nothing to lose, something which also didn’t make a difference.
Finally, I dusted both the plunger and the inside of the solenoid with corn starch(I didn’t have any graphite) which also didn’t make a difference.
Before going to all of these great lengths, I had also spent a good little while smoothing out the drum teeth with an X-acto knife, and then went over them with fine grit sandpaper.
I can’t possibly see anything else that could cause it to stick, however it still is sticking. So, it looks like I may be ordering the spring.
I am wondering if the stop that is riveted to the top e-unit is magnetized? I haven’t heard of this happening, but I don’t know what else could be the cause of the sticking. Do you have a tape eraser? If so, try going over the e-unit with that.
Be sure to order Plunger & Pawl assembly #671-141 along with the Spring as the Spring will not work with any other Pawl assembly. #671-141 has a beveled edge for the spring to fit onto & this is why. Take Care.