Direction change problem

Ed

Start with the basics. Make sure the drivers & track are clean, also polish the collector shoe. Next check your brushes to make sure they are not excessively worn. Also clean the face of the commutator. Make sure the screw at the bottom of the brush plate is tight and that all around it is clean. This is the engines ground. If this does not help, time to tackle the reverse unit itself.

Steve

i've had both stubborn and very sensitive Marx reversing units, but as much as i've seen the problem come up, i've never had one completely stick in one direction or the other.

this may not be identical to yours, but here is a typical Marx electric motor with reversing solenoid and attached headlight...

the reversing solenoid (being the yellow thingie in the upper right) activates a simple toggle switch below it every time power drops out.

below is a closeup of the small hole usually found on the sideframe just below the solenoid...

in that picture, you can barely see a brass rod on the right side of the hole.  this is the physical switch lever that toggles back and forth.

with the motor and headlight working, it doesn't sound like you have a huge problem, but either the solenoid lost power somehow in that quirk you had or something has caused it to stick or jam.

good luck with it.

cheers...gary

Sometimes the reversing hangs up on my Marx 333 and it gets stuck in one direction or another. I've serviced this engine before but the e-unit is tucked up between the motor sideframes where you can't see much of it.

Sometimes you can shake the engine to get it unstuck (for pendulum-type e-units only) and then maybe it will start cycling normally again. Or rap the loco with your knuckles on the cab roof, sometimes that will unstick it. If it needs a little more persuasion, I use a small rubber hammer on one of the domes. (in fact I've been doing more of that lately).

Once or twice I've shot a little WD-40 into the e-unit and it seemed to help - for a while.

The Lionel e-units are more typically at the back where you can turn the drum with a toothpick or something if it gets stuck.

Maybe I'll need to disassemble my Marx 333 eventually - but on some Lionel locos I've replaced problematic e-units with a DPDT switch for manual reversing.

I have some other Marx locos and the reversing works well on most of those.

Do not use WD40. It dries to a brown scum and will stop things from moving.

Get some oil or lube recommended by Lionel for Eunits. It may or may not core the problem, but you won't be cleaning dried oil from the Eunit.

Thank you all for your suggestions. I did some basic cleaning as suggested by Steve and lo and behold the engine moved forward. My elation faded however when after putting the body back on it only ran in reverse again.

Gary, the photos you were good enough to include in your message looked almost like my engine. On mine, the lever switch is on the exterior of the motor but moving it made no difference.

Ace, when I read your post about giving the engine a couple knuckle raps, I thought you were kidding but hitting the plate over the solenoid actually did cause a change in direction. However once I stopped the engine it would go back to staying in reverse. I have not screwed down the engine body to the motor so that I could more easily give the motor another smack to make it behave.

In seeking a more permanent solution, should it become necessary to replace it, what does the reversing unit look like?

Ed

 It sounds like your plunger is sticking. The plunger is at the top of the brass rod shown in the photo's, inside the coil housing. Before you attack taking it appart, try and clean the junk from the plunger and it's hole. Get a can of plastic safe electronic tuner cleaner with the long needle nose spray tip. With the motor assembly out, spray up inside the unit into the plunger area, then shake up and down vigorously. You should hear the plunger moving up and down. Do this 3-5 time to flush the debris out. If you have a air gun, blow it out. Let it dry, then try the motor again. Getting it dry is important, tuner cleaner will go up in flames if a spark gets to it while wet. Don't ask how I know this

If this does not work, the unit will need to be taken apart for a better cleaning.

Steve

I got motivated to fix the sticking e-unit in my Marx 333 loco (before I saw all of Steve's detailed instructions). I think all these Marx e-units are similar regardless of the different loco models.

The 333 e-unit is not real handy to work on because you have to spread the loco motor frame sides to get the e-unit out. Then you spread the sides of the solenoid plunger frame to remove it from the rest of the e-unit so you can get at the parts.

All I had to do was clean out the plunger and plunger bore and reassemble it. The electrical contacts looked good. The photo shows the motor with the e-unit pulled out and the solenoid coil removed so you can see the plunger and pendulum link. Perhaps contact cleaner could have cleaned it without disassembling.

Now my Marx 333 reversing works every time ... but a bit too well: it sometimes trips on Lionel 1022 switches. But I figured that out. The driver wheel gears are about the same diameter as the wheel tread and they can short momentarily to the center rail blob of the switch near the frog. My temporary fix was to put some electrical tape on part of the center rail blob of the switch.

 The e-units are more readily visible and accessible on the 4-wheel Marx motors.

Guys , This is great information I am sure it has been discussed before but the photos really made things clear  and understandable. It is also a great motivator to see the participation of those in the know and there wiliness to help others. Thanks again.

Gary , Lisa and the Girls 

yes it is. I might actually get after my 333, it locked in fwd not long after I got it.

A gunky plunger and cavity are probably 90% of Marx E-Unit issues, maybe even higher on smokers.

Steve

As you can see from these photos, I do not have an easy way to see the plunger. I did apply a little lite oil to where the plunger should be and did some upside down shaking of the motor and voila, my engine is now changing direction again. Thank you all for your advise.

Ed   

Is the on/off switch loose on the reverse unit? It looks like it is barely touching the contact.

Steve... fantastic photos, thanks!

i've never had a frame open up enough to see that detail,  not saying Marx is 100% perfect at my place, but i have enough motors go keep everything i need running.

just a note for sensitive Marx e-units or where track gaps cannot be avoided where running locked in fwd (or rev for that matter) can be achieved by snaking a small wire tie through that side frame hole while the unit is switched in the direction you want locked.  inhibiting the brass rod toggle bar from moving will not damage the unit and is easily undone.  if you want to double-head Marx, i'd strongly suggest this mod.

cheers...gary